unused disc space

[alexandra18]

tried to run a scan to delete previous files and went to tasks run now and clicked unused disc space. it then said not queued and the log said it didn't have the required permissions. How do I run it? This is a stand alone computer

 

[garrett01]

Try using runas Administrator on eraser or turn off UAC.

 

[alexandra18]

what is UAC and where do I uncheck it

 

[GregM]

Start > Control Panel > User Accounts > Change User Account Control Settings > Never Notify