Open Command prompt as run as administrator and then execute the following command. Also, right click command prompt by pressing shift, this will give you an option to run as different user.
Command prompt location: C:\Windows\System32
For Windows 7 or Server 2008 enter this command:
rd /s c:\$Recycle.Bin
For Windows XP, Vista, or Server 2003 enter this command:
rd /s c:\recycler