Dell Inspiron laptop previously running Windows 7 Home Edition I think.

Everything seemed to go smoothly. The new OS does take a bit to load but after a minute or two there is the desktop, for a few seconds anyway. Then it disappears. I've googled around and tried a few of the recommended solutions. Ran explorer.exe from the task manager. When I do that I see explorer in the process list, briefly, as it soon also disappears. I've checked the registry winlogin shell key to make sure explorer is there, which it is. I disabled all the startup stuff. No luck. I tried booting in safe mode without networking and the desktop still disappears after a few seconds. That's when I decided to post. Even safe mode doesn't work.
I can launch powershell and from there run stuff. Anyone experience this particular issue and solve it?