Many of the SSRS administrator I have interacted are a little confused about enabling Report Builder tab. The reason is when the get on the box where they have installed reporting services, they browse to http://localhost/reports they are able to see the report builder tab, but when the try to access the site remotely they cannot see it. To confuse matters future, the administrator keeps granting access to the Report Builder Role and nothing happens.
Below is the step by step instructions on how to enable Report Builder
1. Remote in or log into box where you have installed SSRS
2. Go http:\\localhost\Reports
3. Click on site setting in the Right hand corner, you will get the below from
4. Click Configure system-level role definitions,
Click New Role
5. Add a new role name: Report Builder, Description “This role will make report builder visible to users”
Same as shown above click OK
6. Select Site Setting
7. click Configure site-wide security
When User1 access the site remotely should see the Report Builder Tab.