Capturing DVD playing on computer

I am a magician and have hundreds of DVD's that I want to back up and also be able to play from a USB drive or SD card. I know how to record a the DVD while it is playing on my screen, but I was wondering if this type of recording can be done in the background (like when you set the software to record from a browser in the background) so I can do work on my computer while recording without it capturing the other windows I'm in.

The program that might do that for you would be Replay Video Capture. It has a background feature. Give the demo of it a try and see if it is going to meet your needs.