Windows 7: E:/ Application not found when mounting .iso DVD?

I have some ISOs where whenever I mount them and select "Play DVD" in the autoplay menu, an Error box comes up with the message "E:/ Application not found"
This also happens if I doubleclick on the DVD or right-click and select play.

However, If I open Windows Media Player and access the DVD though it, the movie plays fine.

I don't now what I did to cause this, maybe when I took out my video card (but I don't know if the problem popped up at the same time). It use to work perfectly fine.

Help? Thanks.

Never mind, I fixed it. Apparently it was set to launch the 32-bit version of WMP, which doesn't work. I was using Shark007, so ere's what I did:

1. Launch the 64 bit Shark007 setting app (as administrator)
2. Select the config tab
3. Select "set 64bit player"