I take it that you are planning to upgrade to XP?

Have you tried running the Upgrade Advisor?

http://support.microsoft.com/default.aspx?scid=kb;en-us;307726

follow the links to the download page (eitherXP home or XP pro, whichever you are planning to use). It will, I think, give you the information about each specific piece of hardware for which you need XP compatible drivers.

In any case, you have to identify which hardware requires new drivers, then, knowing also the make of the hardware, you could try the manufacturers' sites to see whether drivers for XP are available. If it is a Dell PC, try the downloads tab on this forum, search with the PC model, similarly if it is another make go to their site and see if they have XP drvers available.

The compatibility site will tell you what issues you may have and I will also recommend you instal and run Belarc Advisor from www.belarc.com and it will give you a total inventory of your system you can print out.  With this inventory you can accurately determine exactly what device(s) you have and need drivers for.