I'd recommend a driver for Win2k since WinXP is more in likeness to Win2k than Win98 (either version of XP). When it says Warning, this isn't signed, just click Install Anyway, and it should be fine.

If it still refuses, you can either search on Google for drivers for WinXP for that printer, or install some generic print driver or one for a similar (but older/lower model number) model printer by the same manufacturer that WinXP does recognise.