Windows 7 - Disk space

Well hello all
When I installed windows I made a partition C 50GB for WIN and D 100GB for stuff
The problem is that C is constantly filling and I am not putting anything in it.
Now I have 7 gigs left and I am searching what is filling it but I can't find anything...
Disk clean up defrags manual deletion.... nothing
Please help me and thanks!

Hi.

Have you been downloading files.
Have you any files saved on 100gb partition. ?

What security do you have. ?

A screen shot of your partitions would help.

Have you tried More OPtions in Disk Clen Up and selected System Restore and Shadow Copies? These can take up quite a bit of space

I am using my D for everything... C is for the windows and some software. I just tried to delete The system restore and shadow stuff... no freed up space...
At the beginning C had 20GB used and than it started filling and filling...
I am using nod32 (original)

I just downloaded WinDirStat and found out that I have 16 gb TEMP folder in C/windows which isn't show in clean up! Now I have freed this space thanks

restore points also take up a heap of space with out telling you. i had more than 20 gig in restore points. so what i would do: make sure your system is clean and stable, then create a restore point, then delete all but the most recent.