Hi John,
On these types of problems, a signature with your computer specs helps. One bad feature of forum signatures with computer specs though, is the graphics driver. If you update the driver reference on your signature, it updates on all your posts, even the old one's, so a 2012 post could have a 2014 driver, which wouldn't make sense. So date the driver and it will contrast the post date for all to see.
[edit] Not sure which video card you're using, but Nvidia can do a clean install using the custom install option.