When we try to change the sql server startup account from the SQL server configuration manager (SQL 2005) we get the following error message:
"No mapping between account names and security IDs was done.[0x80070534]"

Resolution:
-----------------
Execute the following procedure which will report the orphan SID's.
The procedure displays the Windows users and groups that no longer exist but are still granted access to an instance of SQL Server.

EXEC sp_validatelogins
GO

*****After executing the above procedure we will get the groups which had the above problem for example:

SQLServer2005MSFTEUser
SQLServer2005MSSQLUser
SQLServer2005SQLAgentUser

*****We then have to delete these groups from the Windows groups and SQL server logins.
*****We then have to recreate the groups in the Windows:

1. SQLServer2005MSSQLUser$XXXXX$YYYYY
2. SQLServer2005MSFTEUser$XXXXX$YYYYY
3. SQLServer2005SQLAgentUser$XXXXX$YYYYY

Here:
SQLServer2005MSSQLUser---------------------------The Group name.
XXXXX---------------------------------------------------Computer name.
YYYYY----------------------------------------------------Instance name.

*****We then have to recreate the groups in the SQL server logins:

1. XXXXX\SQLServer2005MSFTEUser$XXXXX$YYYYY
2. XXXXX\SQLServer2005MSSQLUser$XXXXX$YYYYY
3. XXXXX\SQLServer2005SQLAgentUser$XXXXX$YYYYY

*****We then have to find out the SID's for the newly created groups and then change the registry entries for the groups AGTGROUP,FTSGROUP,SQLGROUP from the following location:
                HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.x\Setup

*****You can get the new SID’s by executing the following procedure:

     select * from sys.server_principals

*****Once we are done with the above procedure we can change the startup account for the SQL server in the configuration manager.

Please see the detailed steps below to achieve this through clusterrecovery.exe :-

1.Create a new Physical Disk Resource S: through Windows Cluster Administrator and point it to new Windows S: drive.

2.Take the SQL server resource offline in the Cluster Administrator and copy the content of the drive R: to the S: drive.

3.Double click the clusterrecovery.exe and you will get the following screen as shown below. Enter the WINDOWS cluster name and select the option "Replace a physical disk resource" and click Next.

4.After you click next you will get the below screen. Select the old physical disk resource as R (which currently holds all SQL files) and the new physical disk resource as S  and click replace. This will swap the disk signature and will automatically add all the dependency.

5.After you click replace you will see the below screen.

6. Now the cluster admin looks like this:-

7. Get SQL Server online and complete your testing.

NOTE - Don't delete the "R (lost)" resource till your testing is completed. Keep it in offline state.

8. Delete the Disk resource R(lost) after testing is done.