Thanks for the information. From the website you give me, I figured out
how to solve the problem.
To make windows explore show thumbnail for different type of video file
here is what you need to do: (This works on Windows XP with Registry
Editor v5.1, I'm not sure if it works with other versions of windows.)
1. run regedit from Start ---> Run.
2. back up your registry.
3. expand HKEY_CLASSES_ROOT and you will see many extensons, find the
video extension you need to edit (in my case is .ogm and .mkv).
4. Right click on the extenson of your choice and choose New ---> Key.
Rename the new key you created as: ShellEx
5. Right click on ShellEx (the one you just created) and again choose
New ---> Key. Rename the new key you created as:
{BB2E617C-0920-11d1-9A0B-00C04FC2D6C1}
make sure to include the { } sign.
6. Left Click on the new key you created, you should see a REG_SZ value
called (Default). Right click on the value click Modify and put
{c5a40261-cd64-4ccf-84cb-c394da41d590} in the Value Data: box.
7. click OK. Repeat step 3 through 7 for all the extension you want to
edit.
NOTE: Backup you registry before doing any editing. Change registry
incorrectly may corrupt your windows. I only tested this on Windows XP.
I'm not sure if image files are the same registry value.
Let me know if you have questions. Hope this helps