Scroll to the right if you don't see the green circle download link.
The downloads are under two classifications - Drivers and Application software. You probably need both.
You may also need something that can extract files from *.RAR achive files, such as WinRar .
If the ones that support Windows 7 don't also support being installed in XP, then they don't have separate downloads for XP.
In that case, it would be much easier for you to find the CD - you will have to search the web for something such as UTV302 XP drivers
or similar - most of the "hits" that are not for driver finder software you must pay for are in a language other than English and I don't know whether you can choose another language while installing the software.