Hi Raisenkane,
That is a fact, but it is about the manufacturer and not the vendor most of the time. An exception to this statement is usually Lenovo as they tweak around in driver files, but with HP hardware, I have never seen issues. That is why I added the link above as that may help getting the required drivers.
-BBC
PS: You will see that much more often that you cannot get drivers for Vista as WinPE 3/4 are available based on Win7/8 kernels, so not surprising.
PPS: http://windows.microsoft.com/en-GB/windows/products/lifecycle