i looked in task manager and it says literally all the disk is used up when like, 0.2mb is showing up on it
wtf do i do
Are you sure you weren't looking at your RAM and you were looking at your hard drive through Task Manager? As in, I don't think Task Manager shows you how many space is left in the hard drive. Try going to "My Computer" to see how many hard drive space you have left.
As for cleanup you could probably use, one is to try clearing up useless stuff on your hard drive like applications you used only once or games you tried only once.
Next is to make sure that as little programs run on startup as possible.
Another is to get
CCleaner (not a misspelling) and clean up some more stuff that is very likely useless like browser history.
When you can, do try to get specs like Master Matthew said even if you don't know if it'll freeze while you try - you don't have a choice besides doing a format, and you don't want to format over nothing, yes?