It sounds like this is something you mean to do. Up the mem to 256 or greater if you can.
Performance settings to change will get many varied opinions, here are some to start.
Set the display layout to classic view, this looks much like win98. To access, right click on the start menu/ select properties/ tick classic box.
Now right click on "My computer" and select properties. Select the advanced tab. Here tick the best performance box. That disables much of the eye candy. There is and additional advaced tab, go there and tick programs twice and for virtual memory set it fixed at about 300 Meg to start.
I disable system restore and auto update also. (do manual updates).
Next is Services. Access is control panel/ management/ services. The one I disable is Indexing.
That should give a reasonable start. YMMV . Many people shut down alot of services, so they don't get loaded in mem which leaves room for programs. This is fine if you don't need the service. Plenty of room to play around in services.
Jim