<h2>Filename extensions and file associations</h2>

<p>You can probably ignore the Adobe icon and messages from Adobe. </p>

<p>Microsoft windows decides on the type of a file by using the last part of a files name, the part after the last period (dot), called a filename-extension. For example <code>something.txt</code> is a plain text file that can be edited with Notepad. <code>something.mp3</code> is a music file that can be played with, for example, Windows-Media player. <code>something.jpg</code> is a photograph and so on.</p>

<p>Microsoft Windows can also <strong>associate</strong> a particular filename extension with one particular program that understands and uses the type of file that usually has that filename-extension.</p>

<p>Unfortunately a lot of different programs use <code>.dat</code> as a filename extension - it just means some kind of raw <strong>data</strong> file. The Bitcoin Core wallet (sometimes called Bitcoin-qt) uses that filename extension - for example in a file named <code>wallet.dat</code>.</p>

<p>When you install one of Adobe's products (e.g. Adobe Illustrator), the installation process has associated the <code>.dat</code> filename-extension with the Adobe program and removed any association with other programs.</p>

<p>This is why Windows explorer erroneously shows the Adobe icon next to your bitcoin <code>.dat</code> file. This is why Windows runs the Adobe program (not Bitcoin core) when you click on the file.</p>

<p>This doesn't matter that much, you can ignore it and leave the association as it is.</p>

<p>If you run your wallet program by finding it in the start menu or going to its web-page etc (and not by clicking on the <code>.dat</code> file name) it will likely work OK despite the file-association with an Adobe program.</p>

<hr>

<h2><code>bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat</code></h2>

<p>You don't explain what kind of wallet (or web-site service) you used to store your Bitcoins before. The rest of this answer assumes you used the "Bitcoin core" wallet. If you didn't you should stop reading this answer.</p>

<p>The Bitcoin core wallet stores important information in a file named <code>wallet.dat</code> in a place on your computer's hard-disk that is not easy to find using Windows explorer.</p>

<p>If you open Windows explorer and, on the left hand side, click on <code>This PC</code> then <code>Windows (C:)</code>, then <code>users</code>, then click on your name, then at the top click into the part at the top where it says <code>This PC &gt; Windows (C:) &gt; Users &gt; Yourname</code>. It will change to <code>C:\Users\Yourname</code>. Move the cursor to the end (right-arrow) and add <code>\AppData</code> (by typing that) and press the <kbd>Enter</kbd> key. Click on <code>Roaming</code> then <code>Bitcoin</code>. You should see <code>wallet.dat</code>.</p>

<p>The filename you have given is different and is not one I am familiar with. This is a long-shot but,if we assume it is a backup copy of a wallet.dat saved with a special name but the same contents, you might be able to </p>

<ul>
<li>close the Bitcoin program if it is running.</li>
<li>rename the existing <code>wallet.dat</code> to <code>wallet.dat.new</code> (so that you can undo these changes)</li>
<li>make a copy of your <code>bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat</code> with the name <code>wallet.dat</code></li>
<li>put the copy into the same folder as the <code>wallet.dat.new</code></li>
<li>start Bitcoin.</li>
</ul>

<p>If you did not use Bitcoin core, whatever Bitcoin wallet you were using before likely has some "restore wallet" option used in conjunction with data files created using a "backup wallet" function.</p>

<hr>

<blockquote>
  <p><strong>How would I transfer them to a Trezor1?</strong></p>
</blockquote>

<p>This is a separate question, you need to get some information out of your Bitcoin wallet (out of a valid <code>wallet.dat</code> file) and that requires a working Bitcoin core wallet program and knowledge of the password for the wallet.</p>

CC BY-SA 4.0
2020-04-01T18:56:33.537Z
I doubt this is a Bitcoin Core wallet.
Pieter Wuille
CC BY-SA 4.0
2020-04-01T19:04:37.310Z
@PieterWuille: I agree, the more I wrote the more I thought OP more likely has something simpler to use which created his wierdly named file. Maybe the first part of my answer will at least help OP understand file-associations if this is a PC-based wallet of some kind. I'll maybe delete this if any progress is made.
RedGrittyBrick
CC BY-SA 4.0
2020-04-06T16:44:46.753Z
Gents,     Thanks very much for the help so far.  I have gone into the files as eloquently explained above and now have a wallet.dat and wallet.dat.new      There is still an Adobe logo before the file name, maybe that doesn't matter ?
doug cutler
CC BY-SA 4.0
2020-04-06T16:49:32.887Z
When I got the file I did not have a wallet. About 3-4 years later I downloaded bitcoin 0.8.1 and ran it to catch up on the blockchain, which it did. It would update daily.    I could not figure out how to move the .dat file to the wallet and downloaded Bitcoin core. It is now trying to download 5 years of blockchain. Which of these do I delete and how would you suggest i attempt to proceed ?
doug cutler
CC BY-SA 4.0
2020-04-06T16:51:40.180Z
I have the password and a Trezor wallet. Can I skip the bitcoin wallet  and go straight to the Trezor ?
doug cutler
CC BY-SA 4.0
2020-04-06T19:05:07.780Z
@doug: I don't think you can skip that step. So far as I know, you have to [transfer funds into the Trezor by creating a normal Bitcoin transaction](https://wiki.trezor.io/User_manual:Receiving_payments). This means your `wallet.dat` file needs to be used from a working Bitcoin-core program to send the funds to an address created on the Trezor. You probably have to wait for Bitcoin-core to finish synchronising before it will allow you to create a transaction -- You might be able to export the private key, maybe convert it to WIF and then import that into a lightweight wallet (Electrum etc).
RedGrittyBrick
CC BY-SA 4.0
2020-04-08T17:53:01.500Z
RGB     I'm using Bitcoin core, I updated to 19.0 today, it was on 14.0. I'm waiting for the index to update now.  i see that I need to create a wallet with passwords, etc. Once that is done, exactly how do I put the .dat files or open them to move them into the wallet ?   Thanks
doug cutler
CC BY-SA 4.0
2020-04-08T18:01:02.777Z
@doug: you don't need to open the dat files. You can use Windows explorer to rename (e.g. select then F2) and move files - either by drag & drop, by cut & paste or whatever method you are familiar with. I suggest taking great care and first making sure you have several spare copies in several safe places of your `bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat`.
RedGrittyBrick
CC BY-SA 4.0
2020-04-08T19:08:30.397Z
I hate to sound dumb, but am I moving the .dat files to the Trezor/Bitcoin wallet or just to another safe location ?  Can I drag/drop to either of these wallets ? What i find online assumes we are all technically competent. Thanks again.
doug cutler
CC BY-SA 4.0
2020-04-01T18:41:52.550Z
2020-04-01T19:02:34.750Z
2020-04-01T19:02:34.750Z
RedGrittyBrick
<p>Is there a way to convert back or what do I do?   I would have thought that the old dat files would still be somewhere on my PC.  I never put them in a wallet ( .1 BC) so it was just a bunch of files. If i can access them, which ones do I need &amp; how would I transfer them to a Trezor1 ?    </p>

<p>Thank you          </p>

<p>i can find this, is it usable to move the data to my wallet ?   </p>

<pre><code>C:\Users\Doug\SkyDrive\Documents\bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat
</code></pre>

CC BY-SA 4.0
2020-03-31T17:37:06.003Z
What does "converted to Adobe" mean? What does "I never put them in a wallet" mean. That "bunch of files" likely was a wallet.
Pieter Wuille
CC BY-SA 4.0
2020-03-31T18:04:01.847Z
I wanted to "save" the files to be sure to have them in the future. I clicked on the dat file & used the "save file" function. They were on a remote hard drive under bitcoin.dat.   I downloaded Bitcoin Wallet app and can't figure out how to move the data to it to have my .1 bitcoin ( it was a fee download years ago from a newsletter. On my PC, I can only find bitcoin.dat files in Adobe format (?). when I try to do anything it tells me that Adobe can't open them. Maybe that doesn't mean anything. Can I drag/drop into Bitcoin Wallet ?
doug cutler
CC BY-SA 4.0
2020-03-31T18:13:14.597Z
Are they called wallet.dat or bitcoin.dat?
Pieter Wuille
CC BY-SA 4.0
2020-03-31T19:04:08.097Z
What I call pull up all seem to have .h or .cpp
doug cutler
CC BY-SA 4.0
2020-03-31T19:05:59.647Z
That's the source code, and will be useless. Can you please expand your question with information such as exactly what you see, exactly what you did, exactly which software you're trying to use. Perhaps include screenshots if things are hard to describe.
Pieter Wuille
CC BY-SA 4.0
2020-03-31T19:35:59.897Z
Pieter,    cant seem to be able to do a print screen & post it here. Is there an email you use for this stuff ?   The software is/was Bitcoin & Bitcoin Core.   I installed Bitcoin about three years ago & let it run all the blockchain.   About a year ago I got frustrated because I could not get the files to transfer & show my BC. That's when I thought I'd do a save of the files ( had a scare with my hard drive) and then installed the Bitcoin Core because it had a wallet.  In trying to re-access the dat files, all I get now are the ones that look like they are in Adobe format. Thank you
doug cutler
CC BY-SA 4.0
2020-03-31T19:48:25.323Z
I see some old files from 2011 that are qt, qt1, ICNS, orc, and some that are preceeded by a VLC media player icon that says it has 98.1kb
doug cutler
CC BY-SA 4.0
2020-03-31T19:51:22.320Z
I don't do private support, and you should in general not trust anyone who offers you help with recovering funds privately in general - this space is full of scammers. You can add screenshots to your question, or just update the question with all the details you have. That way everyone can give advice.
Pieter Wuille
CC BY-SA 4.0
2020-03-31T20:18:05.407Z
Thanks, sorry, didn't intend to upset anyone, I'm just following instructions & not getting the results I'd imagined.
doug cutler
CC BY-SA 4.0
2020-03-31T20:21:46.010Z
No hard feelings, don't worry; I'm just trying to help. Unfortunately, right now, there is really nothing for us to go on. Please update your question with all the details you have.
Pieter Wuille
CC BY-SA 4.0
2020-03-31T20:25:41.470Z
did that just before your comment about trusting & scammers.    I've tried to do print screen & paste, but I'm being challenged.       I do get this right after the Adobe logo;   C:\Users\Doug\SkyDrive\Documents\bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat
doug cutler
CC BY-SA 4.0
2020-03-31T20:26:56.993Z
Please actually update your question.
Pieter Wuille
CC BY-SA 4.0
2020-04-01T18:16:47.507Z
Please use the [edit](https://bitcoin.stackexchange.com/posts/95046/edit) link that is immediately under your question. Then move the cursor to the bottom of the text-area input box, you can use the icons along the top of that text-area input box to help insert a picture (e.g. a saved screen shot) from your local PC. Or cut & paste extra text at the end or just type in additional information.
RedGrittyBrick
CC BY-SA 4.0
2020-04-01T18:48:50.877Z
Above you're talking about "Bitcoin Wallet app", is that Bitcoin Core, or are you referring to some smart phone app? Please give more information about what you remember. In general you need the same software to restore a wallet; you can't just import something from one into another.
Pieter Wuille
<bitcoin-core><wallet-recovery><trezor>
Saved bitcoin dat file, unfortunately converted to Adobe
doug cutler
# Saved bitcoin dat file, unfortunately converted to Adobe

(Asked by: username_0 on 2020-03-31)

Is there a way to convert back or what do I do? I would have thought that the old dat files would still be somewhere on my PC. I never put them in a wallet ( .1 BC) so it was just a bunch of files. If i can access them, which ones do I need & how would I transfer them to a Trezor1 ?

Thank you

i can find this, is it usable to move the data to my wallet ?

```
C:\Users\username_0\SkyDrive\Documents\bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat

```

**Tags:** bitcoin-core, wallet-recovery, trezor

> **Comments:**
> **username_1**: What does "converted to Adobe" mean? What does "I never put them in a wallet" mean. That "bunch of files" likely was a wallet.  
> **username_0**: I wanted to "save" the files to be sure to have them in the future. I clicked on the dat file & used the "save file" function. They were on a remote hard drive under bitcoin.dat.   I downloaded Bitcoin Wallet app and can't figure out how to move the data to it to have my .1 bitcoin ( it was a fee download years ago from a newsletter. On my PC, I can only find bitcoin.dat files in Adobe format (?). when I try to do anything it tells me that Adobe can't open them. Maybe that doesn't mean anything. Can I drag/drop into Bitcoin Wallet ?  
> **username_1**: Are they called wallet.dat or bitcoin.dat?  
> **username_0**: What I call pull up all seem to have .h or .cpp  
> **username_1**: That's the source code, and will be useless. Can you please expand your question with information such as exactly what you see, exactly what you did, exactly which software you're trying to use. Perhaps include screenshots if things are hard to describe.  
> **username_0**: username_1,    cant seem to be able to do a print screen & post it here. Is there an email you use for this stuff ?   The software is/was Bitcoin & Bitcoin Core.   I installed Bitcoin about three years ago & let it run all the blockchain.   About a year ago I got frustrated because I could not get the files to transfer & show my BC. That's when I thought I'd do a save of the files ( had a scare with my hard drive) and then installed the Bitcoin Core because it had a wallet.  In trying to re-access the dat files, all I get now are the ones that look like they are in Adobe format. Thank you  
> **username_0**: I see some old files from 2011 that are qt, qt1, ICNS, orc, and some that are preceeded by a VLC media player icon that says it has 98.1kb  
> **username_1**: I don't do private support, and you should in general not trust anyone who offers you help with recovering funds privately in general - this space is full of scammers. You can add screenshots to your question, or just update the question with all the details you have. That way everyone can give advice.  
> **username_0**: Thanks, sorry, didn't intend to upset anyone, I'm just following instructions & not getting the results I'd imagined.  
> **username_1**: No hard feelings, don't worry; I'm just trying to help. Unfortunately, right now, there is really nothing for us to go on. Please update your question with all the details you have.  
> **username_0**: did that just before your comment about trusting & scammers.    I've tried to do print screen & paste, but I'm being challenged.       I do get this right after the Adobe logo;   C:\Users\username_0\SkyDrive\Documents\bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat  
> **username_1**: Please actually update your question.  
> **username_2**: Please use the [edit](https://bitcoin.stackexchange.com/posts/95046/edit) link that is immediately under your question. Then move the cursor to the bottom of the text-area input box, you can use the icons along the top of that text-area input box to help insert a picture (e.g. a saved screen shot) from your local PC. Or cut & paste extra text at the end or just type in additional information.  
> **username_1**: Above you're talking about "Bitcoin Wallet app", is that Bitcoin Core, or are you referring to some smart phone app? Please give more information about what you remember. In general you need the same software to restore a wallet; you can't just import something from one into another.  

---

## 1 answers

### Answer by username_2 on 2020-04-01. Score: 1

## Filename extensions and file associations

You can probably ignore the Adobe icon and messages from Adobe.

Microsoft windows decides on the type of a file by using the last part of a files name, the part after the last period (dot), called a filename-extension. For example `something.txt` is a plain text file that can be edited with Notepad. `something.mp3` is a music file that can be played with, for example, Windows-Media player. `something.jpg` is a photograph and so on.

Microsoft Windows can also **associate** a particular filename extension with one particular program that understands and uses the type of file that usually has that filename-extension.

Unfortunately a lot of different programs use `.dat` as a filename extension - it just means some kind of raw **data** file. The Bitcoin Core wallet (sometimes called Bitcoin-qt) uses that filename extension - for example in a file named `wallet.dat`.

When you install one of Adobe's products (e.g. Adobe Illustrator), the installation process has associated the `.dat` filename-extension with the Adobe program and removed any association with other programs.

This is why Windows explorer erroneously shows the Adobe icon next to your bitcoin `.dat` file. This is why Windows runs the Adobe program (not Bitcoin core) when you click on the file.

This doesn't matter that much, you can ignore it and leave the association as it is.

If you run your wallet program by finding it in the start menu or going to its web-page etc (and not by clicking on the `.dat` file name) it will likely work OK despite the file-association with an Adobe program.

---

## `bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat`

You don't explain what kind of wallet (or web-site service) you used to store your Bitcoins before. The rest of this answer assumes you used the "Bitcoin core" wallet. If you didn't you should stop reading this answer.

The Bitcoin core wallet stores important information in a file named `wallet.dat` in a place on your computer's hard-disk that is not easy to find using Windows explorer.

If you open Windows explorer and, on the left hand side, click on `This PC` then `Windows (C:)`, then `users`, then click on your name, then at the top click into the part at the top where it says `This PC > Windows (C:) > Users > Yourname`. It will change to `C:\Users\Yourname`. Move the cursor to the end (right-arrow) and add `\AppData` (by typing that) and press the `Enter` key. Click on `Roaming` then `Bitcoin`. You should see `wallet.dat`.

The filename you have given is different and is not one I am familiar with. This is a long-shot but,if we assume it is a backup copy of a wallet.dat saved with a special name but the same contents, you might be able to

* close the Bitcoin program if it is running.
* rename the existing `wallet.dat` to `wallet.dat.new` (so that you can undo these changes)
* make a copy of your `bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat` with the name `wallet.dat`
* put the copy into the same folder as the `wallet.dat.new`
* start Bitcoin.

If you did not use Bitcoin core, whatever Bitcoin wallet you were using before likely has some "restore wallet" option used in conjunction with data files created using a "backup wallet" function.

---

> **How would I transfer them to a Trezor1?**

This is a separate question, you need to get some information out of your Bitcoin wallet (out of a valid `wallet.dat` file) and that requires a working Bitcoin core wallet program and knowledge of the password for the wallet.

> **Comments:**
> **username_1**: I doubt this is a Bitcoin Core wallet.  
> **username_2**: @username_1: I agree, the more I wrote the more I thought OP more likely has something simpler to use which created his wierdly named file. Maybe the first part of my answer will at least help OP understand file-associations if this is a PC-based wallet of some kind. I'll maybe delete this if any progress is made.  
> **username_0**: Gents,     Thanks very much for the help so far.  I have gone into the files as eloquently explained above and now have a wallet.dat and wallet.dat.new      There is still an Adobe logo before the file name, maybe that doesn't matter ?  
> **username_0**: When I got the file I did not have a wallet. About 3-4 years later I downloaded bitcoin 0.8.1 and ran it to catch up on the blockchain, which it did. It would update daily.    I could not figure out how to move the .dat file to the wallet and downloaded Bitcoin core. It is now trying to download 5 years of blockchain. Which of these do I delete and how would you suggest i attempt to proceed ?  
> **username_0**: I have the password and a Trezor wallet. Can I skip the bitcoin wallet  and go straight to the Trezor ?  
> **username_2**: @username_0: I don't think you can skip that step. So far as I know, you have to [transfer funds into the Trezor by creating a normal Bitcoin transaction](https://wiki.trezor.io/User_manual:Receiving_payments). This means your `wallet.dat` file needs to be used from a working Bitcoin-core program to send the funds to an address created on the Trezor. You probably have to wait for Bitcoin-core to finish synchronising before it will allow you to create a transaction -- You might be able to export the private key, maybe convert it to WIF and then import that into a lightweight wallet (Electrum etc).  
> **username_0**: RGB     I'm using Bitcoin core, I updated to 19.0 today, it was on 14.0. I'm waiting for the index to update now.  i see that I need to create a wallet with passwords, etc. Once that is done, exactly how do I put the .dat files or open them to move them into the wallet ?   Thanks  
> **username_2**: @username_0: you don't need to open the dat files. You can use Windows explorer to rename (e.g. select then F2) and move files - either by drag & drop, by cut & paste or whatever method you are familiar with. I suggest taking great care and first making sure you have several spare copies in several safe places of your `bitcoin (2016_09_09 22_16_58 UTC) (2017_08_22 13_54_01 UTC).dat`.  
> **username_0**: I hate to sound dumb, but am I moving the .dat files to the Trezor/Bitcoin wallet or just to another safe location ?  Can I drag/drop to either of these wallets ? What i find online assumes we are all technically competent. Thanks again.  

---

