Reporting services UAC error is the most common question I get from my team post SQL server 2008 or rather windows 2008, The users often get the below error even if they are a member of System Administrator (Site Setting Configuration) in your reporting services
“User does not have required permissions. Verify that sufficient permissions have been granted and Windows User Account Control (UAC) restrictions have been addressed”
This is when people are really confused when they get a permission error for a system administrator, This is a known issue or rather design by Microsoft when User Access control(UAC) is enabled, more details( http://technet.microsoft.com/en-us/library/cc709691(WS.10).aspx ).
This error is similar to the one in Windows when you get notified to run as administrator to do any file copy/paste even when you are a System admin to the local server. UAC logs in all users with normal privilege and any Admin activities needs the user to explicitly force user to run as Administrator.
You can Resolve the UAC error with Reporting services in couple of ways,
1. Start your IE as Administrator if you are logging in from local and then access the reports.
2. The best way to overcome this issues without much hassle is to add you or the people having issues to “Home->folder setting” with the appropriate role even if you are a system Admin in the site setting configuration. By doing this you can carry out all report related activities without starting IE as Admin without any issues.
3. You can disable UAC which usually is not recommended.
Hope the article helps and Happy New Year!