Deleting files on vista?

a few months ago i had to re-install vista, but usually it just wipes my hard drive, but this time it just stored everything in one folder. I couldnt use any of the programs, and i cant delete the file. I've tried activating and going in on the default administrator account, and i still needed administrator priveliges to delete the files. It's taking up a boatload of space and i just want it gone. How do i do this?