Desktop icons hangup

When I run IE9 a few times, my desktop icons become disabled.
That is, running the cursor over them does not make them highlight. Nor does clicking them cause anything to happen.
Additionally, right-clicking the desktop does not bring up a menu.
I notice that the task manager shows multiple copies of IE9 running.
When I "End Process" on all running copies, the desktop (and icons) start behaving properly.

But the problem is that whenever I run the IE9 program and serf the net, desktop things get messed up again.
Then I have to go and "End Processes" on IE9s in Task Manager again.
Any ideas on how to eliminate the problem permanently?

I have run Malwarebytes and now have zero events in a deep scan.
My antivirus is MS Essentials. Auto UPdates = enabled.

What you're describing sounds to me like it could be a system resource issue.

A few questions:

• Can you describe your system hardware specifications in detail (Make/model, CPU, RAM, HD size)? How much free HD space do you have right now?
• Was IE9 just recently installed, or did you have it installed for a while without any problems?
• Did this behavior start suddenly, or did it appear infrequently at first, to then suddenly start happening consistently?
• Can you remember what was the last thing you did in your computer prior to the problem starting (like installing software, performing system specific activities like a recommended performance tip, visiting new websites, etc)?

(Incidentally, it's perfectly normal to see multiple instances of "iexplore.exe" running when IE9 is running--by default there are 2 and then each additional tab creates a separate process)