I am using the latest versions of Firefox and Thunderbird. I am running Windows 7. I have been having a variety of strange problems this morning.
The minimize, maximize, and close buttons are not working on any browser, nor do they work in Thunderbird. To close out of these applications, I must right-click the item's icon on the taskbar and select close. If I am using Firefox, I can right-click on a minimize, maximize, or close button and select Restore, then I can minimize or maximize -- but only if I stay in the tab I am in. If I change tabs or open a new tab, the buttons do not work (unless I select Restore as described above).
Similarly, the buttons will work in Thunderbird if I right-click one and select Restore. Otherwise, they won't.
At the same time, I've noticed that I cannot move any icons around on my desktop. (Auto arrange icons is indeed unchecked.) Also, none of the buttons on YouTube (volume, pause, etc.) are working.
Any ideas? I've tried running Malwarebytes and Hitman Pro and neither detect any problems.