I'm having small but REALLY annoying problems...

Ok, i hate to admit, i own a Compaq. I'm having quite a few problems because of that...

The comp is a Pentium II 800 with 128MB of ram... :-(

First, i think i have a memory leak or something. After a fresh boot, my resources are at 87%. After about a half an hour of using the comp, they drop dangerously low (about 35-50%) and will not get any higher. Any idea why?

Next, everytime i try to open a folder, the whole screen goes blank and i have to restart...

Then when i get the restore desktop, explore crashes, even though it reloads fine...

Last, I own a Compaq.

Now i'm obviously not great with comps, but i sorta know enough to get by... can someone help?