see the space used for system restore.
in command prompt(run as administartor)
vssadmin list shadowstorage - this will list the shadow storage spaced and maximum space allocated for each drive.
Reduce the maximum soace allocated to a smaller value eg:
vssadmin resize shadowstorage /On=C: /For=C: /Maxsize=2GB This will reduce to 2 GB.
You can use a tool like Sequoia View: http://www.win.tue.nl/cgi-bin/usr/sequoi... to determine where all of your disk space is going.
You can use a tool like CCleaner: http://www.ccleaner.com/download to clear away common temporary files,
Using ccleaner you can delete old IIS and windows log files. This will clear a lot of space. It is advisable to use this tool often to keep the system performance.
