How Do I Stop All Open Browser Windows From Closing Simultaneously

Hello Friends & Experts!

This is a brand new one for me.

I just tried to close one of my browser windows that I had open and ALL of the browser windows, from different sites closed together, simultaneously.  Not just the tabs, but EACH open browser window to different sites, whether minimized, or maximized or big or small, every one closed all at once.  Didn't matter if any of them were secure and otherwise.  Even when I click the Red X to close a pop-up window ad, ALL OPEN IE-7 WINDOWS CLOSE!

Weird...Everything closes!  I've never seen that before! (Outlook, Word, and other Programs stay open.  It's just the browser windows that close)

I checked all my settings and can find NOTHING that seems out of place or wrong.  Can anyone help me stop this?  I want to be able to close each window when I want to, without having all of them closing at the same exact time.  It's like if IE7 shuts down and closes everything that's being viewed with it, no matter if it's a tab or new window. I hope I can get a quick and easy answer.

Thanks in advance!
George Malvar - FreedomWatchdog

* Please Note:
Windows XP SP2 - 1 Gig Ram - Internet Explorer 7 (up to date) System clean with registry up to date, all temps deleted and cookies cleaned. Defrag with Diskeeper-2008 done last night and all worked fine until a few hours ago when this started. (I have re-booted)  

One thing to consider BEFORE this happened) It was taking a lot longer to launch IE7 and get an open homepage window when I first boot up. Then,  it was taking a little longer when I closed my last open browser window - it would even take an extra step to go to as blank before finally closing.  This is before this simultaneous closing problem started