FOR VISTA...

 

>>Right click "Computer"
>>Click "Manage"
>>Double click "Users and Groups"
>>Click "Groups"
>>Right click "Administrators"
>>Click "Add to group..."
>>Click "Add"
>>Click "Advanced"
>>Click "Find Now"
>>Double click "Local Service"
>>Click "Ok"
>>"NT Authority\Local Service" should show up in the list now
>>Click "Ok"
>>Close Computer Management and reboot.