More symptoms

1) The problem is intermittant. Sometimes I can come to the task bar after a while and it will work. I am not sure why. Virus activity?

2) I have one piece of software that assumes that the taskbar is at the bottom and does not work properly, having its top area obscured by the taskbar. I should try unistalling that software but I don't think it is the problem.

3) INTERESTINGLY, *sometimes* when I go to the top right (remember my task bar is at the top) of unresponsive taskbar to where the system clock is displayed, I get a tooltip, one of those little explicative yellow popup boxes, that corresponds to the explanation that should occur I were pointing at a program-top-bar, top right hand corner button, i.e. it says "close" or "return to original size" (by the way I am using a non-English language windows, so my back translation may not be exact).
This suggests, that the problem is some sort of mapping. The OS thinks that there is the top bar of a program (that fad from dark blue to light blue thing at the top of program windows) where my task bar should be.
Hence it could be a registry corruption issue, possibly due to (2) above. Somewhere along the line I have moved my task bar off the top of my screen?

4) It is not only the task bar (and start button) that is the problem. The task manager is one of those windows that always displays on top. When the problem is happening then even though the task manger is displayed on top, I can not click into and activate the task manager. I must use Ctrl + Alt + Delete.