C folder windows disk clean-up problem

I set the C folder windows big enough to have 13G.I would like to know that folder, which can be deleted to save space.

More that is not clear.C disk folder windows big enough to have a 13G – is too high.XP generally no more than 2, VISTA, seems to be no more than 5G.Whether the software installed on the inside? To the point you Reference information:Oh my 2G usually only pay attention to the cause, the software security in the c disk, desktop files too many files in My Documents are too many things to download are in default c disk, the old love not to carry out temporary Internet files Delete and so on!
running xp management tool in the disk clean out the word that will not cause negative consequences, the number of control points with