If you're going to reinsall Windows 7 it would be best, after you have copied out
or made back-ups
of the data you need to save to external media, you could use the Option Three in this tutorial at the link below to do a partition-specific wipe (secure erase
) of the Windows partition to get the best possible space to clean install
Windows 7 to. Partition Wizard : Use the Bootable CD
No matter what you do, if you do a clean install you will have to reinstall all the programs/apps that you use, they integrate themselves into the Windows registry and are not moveable from one Windows installation to another so be sure to save the program activation keys where applicable.
Be sure to post back with any further questions you may have and to keep us informed.