Looks like the Workgroup add-in for Explorer was installed. Unless it is explictly un-checked during your SolidWorks installation it will be installed.
Try doing a repair or modified install of SolidWorks and de-select from the list of software modules to install.
In SolidWorks Explorer, click on the options menu button, and then click on Add-In's and uncheck SolidWorks Workgroup PDM.
Sometimes the menu buttons get hidden, you may have to grab the right hand side of the window and resize the window to show them.
Thanks,
Jeremiah