Wow that sucks! Thing is I know how to fix this as well. I had to wipe my pc and reinstall windows xp last weekend and now its fine. as for loosing your aps.... oops!!! im sure thats made you a little crazy.
btw disc cleanup is not supposed to get rid of everything. the ram has to remember some things, so does the virtual memory if you are running a dual processer
Start, all programs accessories system tools system restore. one and a half months ago. the indian is lying!! do it this way and get back to me. alexbayliss1@gmail.com