Glad you asked:
- Click Start.
- Type the three letters cmd into the Search box.
- Click "Run as Administrator".
- Type the following commands and press Enter after each:
takeown /f "FULL PATH TO FOLDER" /a /r /d y
(This command seized ownership of your temp folder)
icacls "FULL PATH TO FOLDER" /t /c /grant administrators:(X) System:F everyone:F
(This command granted full access to the temp folder for everyone)
Note: FULL PATH TO FOLDER is simply that, the full path to the folder.
Let's say you're trying to delete Old Windows from C:. Your full path would be:
"C:\Old Windows"
Afterwards you can proceed to delete files and folders as usual.