One explanation could be that you have a malfunctioning or malicious add-on in IE9.
You can see if this is the problem by going to the Start menu and clicking Run, type
iexplore -extoff and then click OK. This will launch IE in "Safe mode" (no extensions). If the problem doesn't occur any more, then it’s probably caused by an add-on, and you will need to disable the offending add-on.
To do that, go to
Tools–>Manage Add-ons (enable the Menu Bar if necessary) and scroll through them. The Microsoft ones are usually ok. Look for anything that is marked corrupt or doesn’t have publisher information and disable it. Close IE completely and try to open it normally. Repeat this process, disabling add-ons until you hit on the one that is giving you trouble. If you think you still need that add-on then goto the publisher’s website and look for an updated version.
If the problem occurs also in IE Safe mode, I suggest that you also try the following antivirus products: Malwarebytes and SUPERAntiSpyware.
It might also be an adware infection that is not caught by an antivirus. The following are good anti-adware products: Spybot-S&D! and Lavasoft.
Ensure in all cases that the virus definitions are updated before running a scan. Take backups and ensure you can re-install Windows and all your products, as eradicating an infection can render your computer unbootable.
Actually, the normal advice when an infection is found, is actually to format the hard drive and reinstall everything, but we don't know yet if your computer is really infected or this is some kind of a malfunction.