I was having this same problem. I'm pretty sure it's my DVD drive. I don't totally understand the differences between DVD+R and DVD-R and all that, but I'm pretty sure my problem was my drive being a bit too old.
So...I was able to following method 6 at this site:
Boot From A USB Flash/Pen/Key Drive
and make a USB drive (I used a 4GB one) bootable, then copied the windows dvd files there. Then, went into the BIOS on the affected machine and made it boot from USB first. Worked perfectly.
One thing, after it installs, make sure to go into the BIOS again and bump down the USB device in the boot sequence, otherwise, it'll feel like an infinite loop and keep asking you to install Windows from the USB
Hope this helps someone. Figured I'd post since I spent so many hours in DVD hell. Kept trying new disks, +R, -R, etc, but nothing worked. Go USB if you can, or get a new DVD drive maybe.
Good luck,
Ryan