Chat with an online HP support technician:
http://welcome.hp.com/country/us/en/contact/chat_1.html

I bought an HP notebook with Win Ultimate 64-bit preinstalled.  I have yet to
find a software app or driver that was running on my XP system that will run
in 64-bit mode.  Is there any way to downgrade from 64-bit Ultimate to 32-bit
Ultimate?

Thanks,  Jabe

For HP ssytems: the comp have 2 systems installed on HD (HP recovery
partition) when left from factory. During the initial set-up you choice
which one will be preinstalled on your compm, so the second one will be
erased (answer from HP help desk). Then I suppouse that this secon is
still installed on your HD, but for security reason (Microsoft policy)
no one can tell how to force the computer to initial set-up. One way is
to replace the HD to factory new one; second one just buy the new 32 bit
sysytem and install them. All drivers and software to your HP you can
order from HP support on CDs. Peter