SSRS setup

Tried to bring up http://server/reports and got the error:

The report server cannot decrypt the symmetric key used to access sensitive or encrypted data in a report server database. You must either restore a backup key or delete all encrypted content. Check the documentation for more information. (rsReportServerDisabled) (rsRPCError) Get Online Help Bad Data. (Exception from HRESULT: 0x80090005)

Following instructions here got me nowhere as I got the same error on attempting to extract the symmetric key.

Apparently this is the wrong approach for SQL2K5, I found in the following comment:

For Sql Server 2005 you can change, backup and restore via Reporting Services Configuration Manager.
If you have no backup of the Encryption key you can delete the key and re-create using the change option. BUT BE WARNED!, you must re-enter connection strings and stored credentials in the reports and shared data sources after this.
Refer to the follow technet article BEFORE doing this.

Unfortunately I couldn't get the Initialization to change from x to tick. So I reinstalled SSRS and went through the Reporting Services Configuration Manager step by step to reconnect SSRS services to the SSRS database. At database setup it moaned about existing keys and the Initialization icon stayed as an X. So I went to the Encryption Keys step and deleted keys. At first this didn't look like it had improved things as the Initialization still appeared to have failed, but a refresh updated it to a tick.