  We have undertaken a multi-band observing program aimed at obtaining a
complete census of winds in a sample of WISE/SDSS selected hyper-luminous
(WISSH) QSOs at z~2-4. We have analyzed the rest-frame optical (LBT/LUCI and
VLT/SINFONI) and UV (SDSS) spectra of 18 randomly selected WISSH QSOs to
measure the SMBH mass and study the properties of winds both in the NLR and BLR
traced by blueshifted/skewed [OIII] and CIV emission lines, respectively. These
WISSH QSOs are powered by SMBH with masses $\ge$10$^9$ Msun accreting at
0.4<$\lambda_{Edd}$<3.1. We have found the existence of two sub-populations
characterized by the presence of outflows at different distances from the SMBH.
One population ([OIII] sources) exhibits powerful [OIII] outflows, rest-frame
EW (REW) of the CIV emission REW$_{CIV}\approx$20-40 A and modest CIV velocity
shift (v$_{CIV}^{peak}$) with respect to the systemic redshift (<=2000 km/s).
The second population (Weak [OIII] sources), representing ~70% of the analyzed
WISSH QSOs, shows weak/absent [OIII] emission and an extremely large
v$_{CIV}^{peak}$ (up to ~8000 km/s and REW$_{CIV}$<=20 A). We propose two
explanations for the observed behavior of the strength of the [OIII] emission
in terms of orientation effects of the line of sight and ionization cone. The
dichotomy in the presence of BLR and NLR winds could be likely due to
inclination effects considering a polar geometry scenario for the BLR winds. We
find a strong correlation with L$_{Bol}$ and an anti-correlation with
$\alpha_{ox}$, whereby the higher L$_{Bol}$, the steeper $\alpha_{ox}$ and the
larger is the v$_{CIV}^{peak}$. Finally, the observed dependence
v$_{CIV}^{peak}\propto L_{Bol}^{0.28\pm0.04}$ is consistent with radiatively
driven winds scenario, where strong UV continuum is necessary to launch the
wind and a weakness of the X-ray emission is fundamental to prevent
overionization of the wind itself.
