adding memory will actually increase the resources in XP.
Also clean out your temp and TMP folders. Also search these forums for many articles on how to clean out your computer.
Grif and Toni H are among the Mods with such posts.
Im running XP Professional on a 6 year old compaq presario 5600i desktop 450mhz P3 256ram 13ghd. Problem is after start up there's not enough memory to open the "my computer" icon or the control panel. I have increased the PF, still didnt help. Can I get in somehow to dump some data or do I have to buy another dimm card???