Yahoo Messenger 7.0

I have tried and tried installing Yahoo Messenger 7.0 on my home computer.  I have Windows XP, and no other versious of Messenger are currently installed.  I am the computer administrator, and have double checked to verify the settings are correct.

 

However, when I hit Run, I get the following error message.....You do not have access to make the required system configuration modifications.  Please rerun this installation from an administrator's account.  This is really aggravating.  Any suggestions?  HELP!!!!!!!!!