The nVidia 7300LE is a very low powered graphic card, it's not even as powerful as some recent integrated graphics. It will be able to play some older games, but will give very poor performance in anything recent. Here's a hierarchy chart the 7300LE is on the 6th tier from the bottom on the left side.http://www.tomshardware.com/reviews/gaming-graphics-card-radeon-hd-6870-geforce-gtx-570,2834-7.html
The weakness of the 64 x2 3800+ processor and only 1 GB of RAM will also limit your game playing to older titles. Since you'll (hopefully) be getting a new PC in a few months i wouldn't drop any money on this old PC, but would save your money for a new system. I'd relegate the PC to e-mails and web surfing.
If you had to drop some money on this old system i'd pick up a kit of 2x1 GB of DDR2 RAM and a low power consumption graphic card such as the HD5570.