When I switched from AOL to ATT about 10 months ago, I began experiencing constant IE6 crashes with the error message, "This program has performed an illegal operation...." and "Internet Explorer has caused an error in user.exe blah-blah-blah" under "Details". After several months, I finally isolated the problem as being with BHO's. Disabling "Allow third party browser extentions" in IE completely solved the problem, but, of course, left me without vital functions performed by various BHO's. The tools menu of Spybot S&D showed that I had 3 BHO's, all of which were benign, for ATT, Acrobat Reader, and Panicware Popup Stopper. Since I don't believe that I need the one for Acrobat Reader, or at least not very often, I disabled that, but it had no effect. But when I disabled the one for Popup Stopper, IE worked fine. Popup Stopper seemed to work only if I re-enabled it through the View menu in IE every time I opened a new browser window. Then, about a month ago, I installed Spywareblaster and Spywareguard. Since then, IE has been running so smoothly that it's made me rethink my impulse to go back to AOL. But then recently, I installed BhoDemon and discovered some strange things. There were some changes to my BHO settings that I hadn't made. The BHO for Popup Stopper was enabled and active (which made me aware that it had actually been functioning completely for some time); the BHO for ATT was present but unchecked and thus inactive (which I attribute to the action of Spywareblaster in disabling the tracking cookies that are normally delivered by ATT); and the BHO for Spywareguard was not functioning properly ("there are registry entries, but the file can't be found"). As per the advice of Javacool, I reinstalled Spywareguard to restore the BHO--and the crashes started again! But then when I once again disabled the BHO for Popup Stopper, IE again ran smoothly. Apparently neither the BHO for Popup Stopper nor the one for Spywareguard, in and of itself, was the cause for the crashes. It seems to be a matter of combined configuration. Although it's comforting to have isolated the cause of IE crashes, I'm pretty confused about what's happening, why, and what to do about it by way of a permanent solution. Any thoughts?