Clearing C

I had Vista home basic, on the c drive and I have Ultimate on F, I reinstalled ultimate on c but it created an old windows file folder and I don't have too much space on C. I want to reformat C, is it possible??

I have ultimate running from F.

Please help.

Thanks

do you have the dvd for vista? cause i think if you format the ( c drive ) you will lose your bootmgr file and you'll need the dvd to repair the bootmgr. if you don't have it you may also be able to copy the bootmgr.bak file to your ( f drive ) and then format ( c drive ) then copy it back and rename it bootmgr.ini ( before rebooting).
scrooge