Sweet Image.
If this is happening randomly for the window for more than one thing...
If you have a corded mouse and/or keyboard, try a different one. Individual wires inside the cable can break, often where the cable enters the device, and if the wire ends still touch inside the broken wire's insulation the mouse or keyboard still works but it does erratic things that may make it seem like it is being taken over by something.
You MAY find wiggling or repositioning the cord where it enters the mouse or keyboard makes the problem appear and disappear.
Also check for keys that may be stuck in the down position on your keyboard.
Nick (and Sweet Image)
You should avoid runnning two anti-malware programs at the same time that do the same thing that have a resident component (that runs all the time in the background) - they are likely to conflict with each other.
Norton Internet Security has (a) resident component(s) for both anti-virus and anti-spyware/trojan/adware, and a software firewall that is resident.
That said, I don't know of anything that conflicts with Windows Defender but I find it to be relatively useless and I don't bother installing it anymore.
Some anti-malware you can get has no resident module(s) in it's free version (e.g. AdAware 2008), some do (e.g. SpyBot, Avast!, Windows Defender, AVG 8.x).
Online scanners (e.g. Trend Micro, Panda, Symantec) usually do not require you disable the resident component(s) of the anti-malware on your computer.
If you are going to try running some anti-malware that has a resident component, if something already installed on your computer has a resident component, you should disable that component. In NIS it only allows you to do that for a specified time that you can choose.
In some cases you must un-install one anti-malware program before you can use another one. I don't recommend un-installing NIS unless you must - because of it's anti-piracy feature you will probably have to contact Symantec in order to be able to use it when you re-install it, and it may be a week or so before you can use it again - they have to nullify the original installation record on their web site (it's made automatically in the background while installing the software).
e.g. the AVG 8.x installation will tell you if it detects other anti-malware on your computer it "thinks" it doesn't get along with and urge you to un-install it - however if that other software has already been un-installed sometimes that's a false message due to stuff left behind in your registry.
I don't know if Superantispware has a resident module or not. Go to their web site and look for info about that.
It is easy to disable the Resident Shield in AVG 8.x.
I have had no problems running Malwarebytes without disabling the Resident Shield in AVG 8.x.
In any case, it has become very apparent in the last few months that these days, more than ever before, no one anti-malware program can detect everything.
