Hey Henry Gibson
PDM-preview window is using eDrawings to show you the 3D-model. There is most likely something wrong with your eDrawings install or perhaps with the display drivers etc.
Try to reinstall eDrawings to fix your problems, you can download eDrawings separately here; eDrawings Download Check | SOLIDWORKS
If you can't install it separately you might need to repair or reinstall your whole SolidWorks / PDM installation.
You can check for latest display drivers by running SolidWorks RX-software which should be installed if you have solidworks at your computer. Diagnostics tab contains info about your display driver and link if there is a newer certified driver available.