|Sure, upgrade your RAM to 2GB...that alone would make Win7 run approximately 84 times faster. |
You could also add a bigger, faster hard drive. Those old 40GB drives are slow, and yours is probably at least half full.
Find a cheap Radeon 9600XT on eBay to give older games a boost and enable Win7 Aero Glass. Anything faster than the 9600XT would be held back by that slowpoke processor and probably overstress the power supply.
If you want to play new games, you'll have to bid that PC adieu and begin anew.
HTPC | Pentium M @ 2.82GHz | 4GB | 1.0TB | Radeon HD5750 | Blu-Ray | Win7 Pro | HDMI out to Onkyo TX-SR707