To convert documents from earlier releases to the current release of SOLIDWORKS, use the SOLIDWORKS Task Scheduler.
When converting Workgroup PDM vault files in SOLIDWORKS Task Scheduler, all documents open in a resolved state (not lightweight). Make sure the computer on which you run the conversion has enough memory to complete this procedure.
You can reduce conversion time by using more than one computer (convert different projects on different computers). Log in as the same user on each computer because the vault is locked to everyone but one user during the conversion.