WMP 12 does not play video if stored on non-OS hdd

Anyone have any ideas how I can fix this?

I have a set of h.264 files (mp4). When these videos reside on the C: drive WMP has
no problem playing them/streaming them. But, once I moved them to another internal hard drive, to a non-os drive, and re-add the new folder to WMP library, WMP sees the files but only displays a black screen and plays audio.

Now, please do not go off on a "codec" tangent, because clearly if WMP can play the files if stored on the C: drive it has the codecs to play them.

The reason I need to store the files on a non-os drive is because I just got a new SDD drive that is not large enough to accommodate video files.

Thanks

I don't believe you have a codec issue either. That's rather some form of rights conflict.
Try to take ownership of the directory and/or the movie clips.

Take Ownership Shortcut

-DG

If it was an ownership issue, the audio wouldnt play either. Are you sure the files didnt get corrupted when you moved them off the OS drive? Try copy-pasting again.

Also, can you play the files with VLC or Quicktime?

I don't think they got corrupted because I moved the files to non-os drive and didn't work. Then moved them back again. So a copy from the non-os drive and pasted to the os drive, and worked like a charm. VLC and GOM play the files without issue, both the non-os drive and os-drive files alike.
I will give the ownership option a try and report back.

If VLC and GOM play the files fine, its possibly a WMP quirk. Try this WMP troubleshooting guide.

Windows Media Player Troubleshooting Guide