For those who are using
HDV Split to download their HD footage to their computer, you may notice that thumnails are not generated (which gets frustrating with 100's of files)
I found a solution
here that a number of other people and forums confirmed that it worked... so i tried it out and kazaa it works

The instructions on how to get it working.
Open
Notepad and paste in the following text
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\.mts\ShellEx\{BB2E617C-0920-11D1-9A0B-00C04FC2D6C1}]
@="{c5a40261-cd64-4ccf-84cb-c394da41d590}"
[HKEY_CLASSES_ROOT\.m2t\ShellEx\{BB2E617C-0920-11D1-9A0B-00C04FC2D6C1}]
@="{c5a40261-cd64-4ccf-84cb-c394da41d590}"
[HKEY_CLASSES_ROOT\.m2ts\ShellEx\{BB2E617C-0920-11D1-9A0B-00C04FC2D6C1}]
@="{c5a40261-cd64-4ccf-84cb-c394da41d590}"
Save the file as
AVCHD Thumbnails.reg
Then double click the file which will run it, then accept the merge.