no problemo. That's sort of what I'm here for; replying.
Okay, the bad news is that if you tried multiple disks that work in other dvd players but not yours, guess where the bad link is. Yes, your dvd player. Even if you can play other dvd's, something is hinky in your player.
start > run > devmgmt.msc > enter > expand dvd/cd rom drives > double click the device > check to see what region it's set to. Then check the region your buddies is set to, and see if they match. Do NOT go randomly changing the region, as you only have a set amount, and it's not many (3 or 5) and then your dvd will not work anymore period.
But at least check to see if you both in the same region. That is where I would start. If you see that it is different, don't change it right off; do some research, or post back here before changing it, as again, you only have x amount of changes to be made.
thanks,
v