Hi!
Probably you've already solved that or reinstalled the system by now. Anyway, I had the same problem and what did the trick was opening elevated command line - from start menu type "cmd" in the search box, right click on cmd.exe and run as administrator. Once you are in the command prompt type "regsvr32 shell32.dll". You should get confirmation if successful. This will re-register Windows shell library, which is responsible for how windows explorer operates. Remember to restart the system and it folders should open in the same window as you want them to.