Windows 7 Video Thumbnails

I hope this is the correct place to post this first time post. I have done as much research as I can find on my problem and read other people's questions, but haven't been able to find the solution to viewing thumbnail previews of videos. In Vista, I could see all the video previews, now I can't after installing Windows 7. I have updated my videos drivers, downloaded all the latest codecs, but still get only a black preview shot of the video. This is really frustrating for me since I do video editing work for people. If anyone can help me, please give me some suggestions as I don't want to have to reinstall vista as a last resort. I have went into windows explorer and checked the box for show thumbnail icons in the file folder also. Then I deleted the thumbnail cache and still no luck. Sorry for being so long winded.

SoulSeven said:

downloaded all the latest codecs

This is where your problem is.
Uninstall whatever it is you have previously installed for codecs and use the Shark007 Win7codecs.

To see Video Thumbnails as Thumbnails not Icons:

From the Start Menu open Control Panel (All Items vew), and click on the "Performance Information and Tools" icon.
Click on the "Advanced tools" link in the left blue pane.
Click on the "Adjust the appearance and performance of Windows" link.
From the Visual Effects settings check: “Show Thumbnails instead of icons”