The SQL Server Reporting Services (MSSQLSERVER) service failed to start due to the following error: The service did not respond to the start or control request in a timely fashion.

The SQL Server Reporting Services (MSSQLSERVER) service failed to start due to the following error:

The service did not respond to the start or control request in a timely fashion.
Click Start, click Run, type regedit, and then click OK.
Locate and then click the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
In the right pane, locate the ServicesPipeTimeout entry.
Note If the ServicesPipeTimeout entry does not exist, you must create it. To do this, follow these steps:
On the Edit menu, point to New, and then click DWORD Value.
Type ServicesPipeTimeout, and then press ENTER.
Right-click ServicesPipeTimeout, and then click Modify.
Click Decimal, type 60000, and then click OK.
This value represents the time in milliseconds before a service times out.
Restart the computer.

Credits 

http://weikingteh.wordpress.com/2012/06/29/cannot-start-sql-server-2008-r2-reporting-services/