Preview box when you hover toolbar icons disappeared?

ok I enabled the windows restarted and everything seems to be ok, I really dont know what I did other than restart.

I have been updating/downloading/adding tons of programs onto 7 over the last 8 hours.

Now its back to not doing it. I dont know. I'll try restarting again in a little bit.

This doesnt make any sense.

I've noticed the exact same problem today - fixed (apparently) by a reboot. The only system change I recall making today was installing a newer version of the '7 Sidebar' gadget (that makes the sidebar more like the Vista version).

It will be interesting to see if it stays fixed or not!

Cheers,
--
Neale
Insanity is hereditary, you get it from your children

First post.
Hope it helps.

Problem In Windows 7, when you hover your mouse on taskbar icons, it will display small thumbnail preview of opened window on your taskbar, but if you are not comfortable with taskbar thumbnail previews feature, you can disable it. Solution
Open Local Group Policy Editor. To open Registry Editor, type in "gpedit.msc"in Start menu search box and hit enter to validate.

Navigate to "User Configuration->Administrative Templates->Start Menu and Taskbar" in the left pane of Local Group Policy Editor.

In the right pane, find and double click "Turn off Taskbar Thumbnails".

To disable taskbar thumbnails preview, check "Enable" and click "Apply". To enable taskbar thumbnails preview, check "Disable" and click "Apply".

Click OK button to finish setting and restart computer to check your taskbar for thumbnails preview.
Tips
Taskbar Thumbnail Preview only works when you have turned on Aero in Windows 7.