When running the Convert Workgroup PDM Files task, from SolidWorks Task Scheduler. If you cannot proceed past login screen, you need to install the SolidWorks API component.
From the windows control panel, select Uninstall a program.
Right click on the SolidWorks installation and choose Change.
From the welcome screen of the SolidWorks Installation Manager, select Modify the individual installation (on this computer).
Click on next until you get to the Product Selection window, select API tools and click on next. You should now be able to run the convert ask.