I had a difficult time installing Huffyuv on Vista 64-bit, but found an article on videohelp forum that clarified it. The step-by-step is modified somewhat, due to problems running command prompt... so I've included the workarounds for that too.

NOTE: I copied the contents of the Huffyuv codec folder to a "Temp" directory on my C drive to keep the Step 4 path address simple.




Go Start


Type "cmd" in the run box and press Ctrl+Shift+Enter to run in Admin mode
If the command prompt window doesn't say "Administrator: Command Prompt", step 4 will not work


Navigate the command prompt to directory SysWOW64 with the cd command: "cd C:\Windows\SysWOW64" Type the following, then hit enter:"rundll32.exe setupapi.dll,InstallHinfSection DefaultInstall 0 c:\Temp\huffyuv.inf" If the Command Prompt gave no error messages, you should be good-to-go.




If the Command Prompt DID give an error message, it probably wasn't running in Admin mode. To make sure it is, do the following:

click Start
in the Start Search box, type command... a list of matches will appear.
right-click Command Prompt in Programs list, then choose Run as Administrator.
if admin confirmation or password comes up, type your password or click Continue.

You'll need to be using the Vista Start menu (not Classic Start) for the above to make sense: go Taskbar and Start Menu Properties and select "Start menu".



SOURCE REFERENCE (with pictures!)
http://forum.videohelp.com/topic332208.html
http://www.geekstogo.com/forum/Windows-Vista-run-command-prompt-administrator-t146674.html

thanks for the info. Hadn't even tried, because I've read other posts that have indicated problems.
Many thanks.