Browsers: Internet Explorer uses all available CPU and hangs

Internet Explorer uses all available CPU and hangs

Several months ago I upgraded IE from version 6 to version 7 or 8 on my laptop computer (I don't actually remember which version of IE I upgraded to ... it was whatever was current in the May/June time-frame).

Within a few weeks of the upgrade, I noticed some odd behavior in IE ... every time I launched it, cpu would spike to 100% and there would be a delay anywhere from 10 seconds to 2 minutes before IE actually finished initializing and became usable (at which point cpu utilization went back down to normal).

Over about 2 months that delay and period of max cpu utilization kept growing longer, until finally (for about the last 6 weeks) IE does not ever become responsive -- CPU at 100% and IE completely unresponsive, and I've walked away from the pc and let it sit for over 2 hours with no change ... cpu continually maxed out, IE unresponsive.

I can launch and use Firefox as well as Chrome (haven't installed or tried other browsers) with no apparent problems -- it's only IE that is broken.

I "uninstalled" IE, downloaded and installed IE again, but nothing has changed. If I try to launch IE, cpu maxes out and IE never becomes usable.

Can anybody suggest any troubleshooting methods? Things to check? Could it be some kind of browser add-on that is broken (something left over from the original IE6 installation)? And if so, how can I delete add-ons if the browser won't launch?

tia!