I would think a reformat is in order. How long has it been since you installed your windows?
Also you can tell us if you are using a 32bit or 64bit version of the windows. If you are using 32bit then that might be the problem since 32bit only uses upto 3.5gigs of memory.
Not sure when Windows was installed. A friend gave me this computer, but it's kinda been like this as long as I can remember. I've just always dealt with it. 64 bit Windows btw. I guess I'll order up a Windows replacement disk and reformat.