System restore was not helpful, unfortunately.
So I uninstall IE 8 and returned back to IE 7...but still not working. I choose the Normal Startup for windows vista services from msconfig. Reinstall IE 8. Disable Protected Mode for Internet Explorer (Internet Options > Security > uncheck Enable Protected Mode.
Now it's working.
For all those (like me) who use 99,9% Firefox, there's a useful plugin for Firefox 3 called IE Tab. With this plugin installed, you can open every pages that need IE (like microsoft updates). No need to use IE anymore
Have a nice day