Delay Accessing Toolbars Or Start

The system is a vista x64, Dell machine with Vista pre-installed. I had trouble and had to re-install the Vista from their supplied disk. The system appears to boot up and run normally, EXCEPT that most of the time when I move the cursor over the taskbar none of the items will highlight and cannot be accessed. This can take up to 10 seconds or so of waiting for them to activate. It happens about 75% of the time that I try to activate something fro the taskbar. This involves the entire taskbar including quickstart, start and any active programs. If I hit the "CTL-ALT-DLT" and cancel it becomes active immediately.