I you got problem starting your DPM RA service it’s a good thing to verify that your ACL for the “Launch and Activation Permission” is correctly configured.
To verify this click START and type dcomcnfg, this will open the Component Services.
Expand the Component Services / Computer / My Computer /DCOM Config. Right click the DPM RA Services and choose Properties.
Under the Security tab click the Edit… button in the Launch and Activation Permissions to open the ACL.
Verify that the DPM Server has all the Allow checkboxes marked.