Q: Multiple conditions in formatting Excel cell I need to write a text into a cell, based on the value of another cell, for instance:
Cell G1 have value blank and H1 have value 0%; I need to write "In progress" into G1 cell when the percent value in H1 is more than 0%, "In progress" if the value is between 1-99%, and Completed if the value is equal to 100%.
One part is achivied using =IF(H1<> 0%, "Work in progress", "To be started")
But When I try to specify two conditions: =IF(H48<> 0%, "In progress", "To be started", IF(H48= 100%, "Completed"))
I got the error  

"you've entered too many arguments for this function"

What's wrong?

A: you could use
  =IF(ISBLANK(H1),"To be started",IF(H1=0," ",IF(H1<1,"In progress","Completed")))

You need to have IF(test condition, true result, false result) even if embedding another IF.
So with:
=IF(H48<> 0%, "In progress", "To be started", IF(H48= 100%, "Completed"))

test: H48<> 0%
True result: "In progress"
False result: "To be started"
Instead of embedding another If as a false result test you have added a non existent additional parameter after the False result.
IF(H48= 100%, "Completed")

I think you may have missed a condition result or at least some logic:
I think you want:
If empty then "To be started"
If 0 then "insert text here"
If <1 then "In progress"
Else "Completed" Though this could return Completed for a text value for example in which case you want another If = 1 then "Completed"
So maybe something like:
=IF(ISBLANK(H1),"To be started",IF(H1<1,"In progress",IF(H1=1,"Completed","Unknown")))

Or if you do want the zero test (as per comments) in: 
=IF(H1=0,"To be started",IF(H1<1,"In progress",IF(H1=1,"Completed","Unknown")))


A: Try, 
=lookup(h1, {0, 0.01, 1}, {"", "In progress", "Completed"})


