Here's what I did. I downloaded this file:
and copied it into c:/windows. Then I found the comctl32.dll file in the C:\WINDOWS\system32 folder and renamed it oldcomctl32.dll. MS file monitor came up and warned me about changing file names but I let it keep the changes.
Then I took the newest copy of the comctl32.dll from C:\WINDOWS\WinSxS\... and copied it into the system32 folder. Reboot and all the tabs are back. I still have an issue with my video driver, but that's easy compared to this.
thanks for all the help and thanks to Metallica, phantomass, makai and Lorijan for figuring this one out.