OP, you should try to do these things:
1.
Speccy might be able to tell us a bit more about your computer. Especially the motherboard model.
https://www.piriform.com/speccy
download said program and post pics of the specs
2. get rid of XP whenever possible; it's time is up and get to windows 7 64 bit at least(32 bit will only barely support 4 gigs of ram, so if you ever really plan to upgrade, you'll also have to dump the 32 bit OS (not 32 bit programs though, there is backward compatibility but not for 16 bit programs iirc(which you shouldn't even have anymore in 2014))
3. get more ram for windows 7 because 1 gig will barely cut it, 2 gigs at the very minimum for satisfactory(depending on your standards) speed(IF your computer can be upgraded) I know this from currently using windows 7 with 2 gigs of ram
4. if you plan on updating your GPU and CPU aswell, you need to ensure compatibility and that the PSU will give them enough power, since chances are if it was a prebuilt, it will be only 250-350 watts or so which isn't really enough for anything great.