Keeps saying a system restart is required, fails to extract files but says its complete.

I have donwloaded Photoshop Elements 14 Upgrade 3 different times.  At first I installed the installer they recommended then from there downloaded the files.  It seems to download them all, then appears to extract them, but then says an error occurred and a system restart is needed.  I have done this 3 times and wasted a lot of time.  What do I need to do to get this installed.