This may not be what you are looking for....
Are you referring to Windows.old folder ?
If yes, and if you have CCleaner installed, you can use it to remove windows.old.....
Open CCleaner > left side, click Windows tab at the top > scroll down to Advanced section > you should find "Old Windows Installation " entry > check the box > click Analyse which will tell you how much disk space will be retrieved > click Run Cleaner.
You can also use the built-in Disk Cleanup program to remove Windows.old
http://windows.microsoft.com/en-ca/windows7/how-do-i-remove-the-windows-old-folder