Windows 7: my taskbar is disappeared!

After computer sleep and i wake it up again, my taskbar is disappeared but it has only 'start button' and everything is running as normal only taskbar disappear (see attachment).
It will show again after i restart the computer.

- I have alreadys restored my computer.


what should i do first to know what the problem is?

thank you very much for any suggestion

_______

I am running windows 7 x64 build 7600

hm...interesting

You didn't perchance "customise" Explorer in any way, did you? Patch UxTheme or something along those lines?

no, i'd never editted any Explorer.

i've tried task manager by endding process named "explorer" and re-running it

so, it does restore my taskbar but i really want to know what exactly causes this problem.

If you're quite sure Explorer is not customised or patched...

Have you installed any "desktop extenders"? Ultramon, that sort of thing.

Are the BIOS and video driver up-to-date?

Does the same thing happen if you use MSCONFIG to select "diagnostic" mode and reboot?

Nope. I'd never installed any desktop extender.

I'd already rebooted using you recommend.
After i pressed sleep button in "diagnostic mode", my computer didn't go to sleep mode and just crashed. So i cannot wake it up normally and have to hard reset.
Furthermore, i confused that i tried again by sleeping it in "normal mode" and it went normally, then woke it up, the taskbar was fine.

+ this problem occured after i installed Xiph codec to read .ogg and .flac files but i've alreadys uninstalled it.

+ i'm not sure about bios driver but display driver is up-to-date

Again, thank you very much for your help.

The problem has been treated here :

Windows 7 Taskbar disappears overnight - Super User

Have you run the same screensaver (Fliqlo)?

What has happened is you probably moved your mouse in between your screen saver and desktop.
Try previewing your screensaver usually fixes it for me.

I have the same problem when I come out of a program called KeyWack (It's for my 2 y.o. grandson to play with).

I usually have to log out and log back in to get my taskbar back. Not TOO much trouble when it keeps the 2 y.o. occupied for more than 2 minutes.