Couple of possibilities:
* Suspected culprit #1 is a virus. It's fairly typical. Loading up a fellows computer with malicious junk. Probably temp files and there could be thousands.
As a matter of principle I never recommend software. However, there are programs to remove empty files that are purported to be effective and sometimes end the problem.
Too Windows 8 has some trouble shooting features and self fixes that you can run.
I have run Spybot, Search & Destroy and it worked for me. It does come with the Good Housekeeping Seal of Approval from some serious experts. It is free with no gimmicks or strings.
* Possibility #2 is a feature of Windows 8 that auto saves files and these can become hugely voluminous. Very recently, in the past few days, or so, this problem cropped up here and the remedies were posted. They apparently worked.
Most likely the moderators, and/or posters, who remedied it can guide you to the posts. They are quite good at that.
