So suddenly this bug cropped out of nowhere and started bugging me by clouding the entire desktop with open windows.
Googl-ed a bit and found out that many people have been having the same problem. Tried the quick fixes mentioned but to no avail.
Then tried my own method. Went to start (I have a windows vista home premium edition). Typed windows explorer. Right clicked on windows explorer and select run as administrator. user account control pops up and asks if you want to proceed. click yes. Then the “SYSTEM USER NAME” folder opens up (in my case “SID”). In vista the menu bar is hidden by default. press the Alt key to bring it up. go to tools. select folder options. and under general tab select ‘open each folder in same window’ click apply then ok. You are good to go. Check now if the problem is resolved. Double clicking will open folder in same window and if you right click and select explore the folder opens up in a new window.
Cheers & Beers