Okay, no matter how many times I insert the DVD, the driver never detects it. I restarted my pc and tried again but it didn't help. But when I put in other DVDs, it works fine.
Is it a bootleg DVD? Sometimes those are hit or miss. Another problem I've run across is the zone is from the wrong country. Have you tried playing it on a set top player?
First thing: Try to play it on another DVD drive (EG a friends laptop). If you can, then there is some fault with your drive. Check the region of the DVD and DVD drive (it should say on the back of the DVD box, and to find out your DVD drive's region install drive info (http://www.digital-digest.com/dvd/downloads/showsoftware_driveinfo_3.html). It should be set to region 2, as should the DVD). If it doesn't work on another drive, then the DVD is probably faulty, so get it replaced. The store you got it from should replace it for free providing its faulty.