User1535942433 posted
Hi jagjit saini,
According to your description,it's because of lack of privilege for the user you are running the report builder, just give that user or a group a privilege to run report builder.
You could do like this:
1.Start Internet Explorer using "Run as Administrator"
2.Open http://localhost/reports
3.Go to properties tab (SSRS 2008)
4.Security->New Role Assignment
5.Add DOMAIN/USERNAME or DOMAIN/USERGROUP
6.Check Report builder
Best regards,
Yijing Sun