Alright, the answer to this question may or may not be obvious. When I play a music file, I can record the same music file by opening any sound recorder program and changing the input to 'Wave Out Mix.' Is there a way to do this with video being played? For example, if I played a DVD and wanted to record a five-second segment of it. Now I have tried screen recorders, which usually work, but for some things like DVDs screen recording won't work and simply shows a black square. I suspect this is due to overlay problems. In case you need to know, I use Windows XP (yes, XP as in dead) and I usually use Media Player Classic to play things.

...I was never good at conclusions.