My windows directory is huge

Solution 1:

In Windows Vista and 7, The Windows directory is not actually as large as Explorer tells you it is. In these versions of Windows, there are a large number of NTFS junctions (hard links) in the Windows/WinSxS directory which point to other files on the disk. Explorer will dereference these junction points when calculating the size of the directory, so a single file may be counted 2, 3, 4 or more times. (ref.)

Solution 2:

Run WinDirStat and see if you can find any unusually large files. The program displays all of your files graphically:

Sometimes you can find a large corrupted file that is entirely useless.