Windows 7 Question Taskbar full screen thumbnail preview just show black rectangle


New Member
My 1+ day Windows 7 was good.

Now, when I mouse over over the taskbar, the full screen preview no longer shows the thumbnail. Instead, it shows a black rectangle :-(

Besides this, everything is fine. Windows 7 is great.

My hardware is a new desktop with MSI motherboard, Core2 Quad Q8200, 8 GB RAM and ATI graphic card. Everything, except the SM Bus, was recognised, and proper driver was installed. Windows Experience Index is 6.1 for graphic and 7 for others.

The SM bus doesn't seem to be related, as the taskbar was showing proper preview earlier.
Much appreciate help.

Thank you from Singapore