I think this is the worst laptop hp has ever made. It has no cooling fan inside to cool down the CPU temperature.Neither it has proper heat sink for the CPU. It has a problem of frequent freezing with Blue Screen of Death.
As per the service desk technician windows-7 is not compatible for this model. On the other hand, hp has published device drivers for the different devices/hardware of this laptop for Windows-7(various versions).
We have tried to run this laptop with different operating systems like Win-7, Win-8.1 . But found the same result in each case.It has a problem of over heating, slowness, lag in opening different applications at a time.People should not buy this product as per my opinion.