Ed,
Simple check. Uninstall Google Chrome and see if the problem goes away and you get your normal Windows Desktop.
Also, Be aware that if you do not have some active Anti-Virus software running, you may have picked up a virus. There are many software download sites that have viruses or spyware attached to their downloads. You may think you are downloading Chrome directly from Google, but that may not actually be the case.
My new Dell PC came with the standard Microsoft Security Essentials installed but within a few days I continued to get all sorts of pop-ups and my Chrome was high-jacked to got to other websites. I eventually had to switch to AVG anti-virus, anti-spyware, and delete all Chrome Extensions! I like Chrome and use it on all my computers but found that Window-7 and Windows-8 are prone to letting Chrome Extension install without your knowledge or authorization. My old HP running Windows XP Professional has never had the problem with unauthorized Chrome Extensions...and I got to a lot more riskier websites with my old XP machine???
I think there is some vulnerability with Google Chrome and Windows-7 and 8?
I tried to load Windows-7 on my old Laptop and it went out of control. I could not connect to any website I wanted and was alwasy redirected to dozens of other websites that would pop-up every few seconds! My only choice was to reformat the harddrive and restore my old XP operating system, delete all Chrome Extensions, and install AVG to protect my computer from Viruses and Spyware. That was over 6 months ago and everything is running fine now.
When you download AVG, you can turn on the Pro version for 30 days, and then if you decide you don't want to purchase it, there is an option when you uninstall it, to revert back to the FREE version, and it works great!
...Rich