Run the following commands from command prompt to un-register the plug-in:
regsvr32 /u C:\Program Files\Altiris\Altiris Agent\Agents\Symantec SRMS Agents\BackupAgent.dll
regsvr32 /u C:\Program Files\Altiris\Altiris Agent\Agents\Symantec SRMS Agents\BackupTaskAgent.dll
Run the following commands from command prompt to register the plug-in:
regsvr32 C:\Program Files\Altiris\Altiris Agent\Agents\Symantec SRMS Agents\BackupAgent.dll
regsvr32 C:\Program Files\Altiris\Altiris Agent\Agents\Symantec SRMS Agents\BackupTaskAgent.dll