Why coming back to old XP?

You've the same sound card that I have. You could have tried Daniel_K drivers before the XP install (
http://forums.creative.com/t5/Sound-...LS/td-p/549311). That worked awesome for me. I'm currently using equalization, CMSS Surround, Crystalizer and bass redirection on my 5.1 sound system. Not to mention that this drivers are full supporting EAX for my games.

About your HP printer, I didn't know any model that doesn't works on Windows 7. Some models doesn't have drivers for Windows 7, but have for Vista and those works on 7 too... try giving me the model, I could help you.

By the way... a router USING DRIVERS? That sound odd for me...

Which brand and model?
About your motherboard's chipset, use Vista drivers. Those drivers works fine for nForce 4.
The other devices you've all have Windows 7's drivers.
Now, you choose:
1) Your creepy old XP 32 bits with poor performance (even more poor when you finish doing Windows Update

)
2) The creepy XP 64 bits edition that has incompatibilities everywhere and isn't much faster than his 32 bits brother.
3) Get rid of your incompatibility issues and use a superior, more efficient and beautiful software like Windows 7 x64 is.
Hope you make a wise choice.