Most windows operating systems will install many 56k/v90 modems, but you have to be careful in the v/92 modems, some will cause hardware issues ( I currently have one that does on a P4 system, Conexant, which manages to at times conflict with (or bump heads with other programs and hardware, and knock out my com port), which I removed it and installed my older 56k/v90 (Lucent) modem without any issues, and everything works fine, in a multiboot environment ( I boot with boot magic 8, Windows 98 Second Edition, Windows 2000 Professional (SP3), and Windows XP Professional (SP1). Check the chip on your modem to see which chip it contains ( usually it is on top of the main chip), as well as check your literature that came with your modem to see the type of modem it is. Most HP Vectra's are P2 class systems, ( I have a friend of whom I installed from an older 98 (4.10.1998 upgrade from windows 95 (shipped with it), to a clean boot of Windows 98 Second Edition, which everything worked fine.