Aside from removing files that you don't want or need here are 3 simple ways to reclaim space.
1) Reduce the size that Windows uses for the recycle bin.
2) Reduce the amount of space that Windows uses for restore points in system restore.
3) Reduce the amount of space that IE uses for temp files.
I also noticed in another post of yours that you were working with fraps and creating 150 MB vids or larger. I can almost guarantee you that those temp files are still residing on your drive after all was said and done. Clean out all your temp files using the tools provided for disc maintenance then defrag, reboot and defrag once again in safe mode.