can't install 8 or lite

I have an older Dell computer that has/ runs windows xp, It has one gig of memory and a 12 gig hard drive. I am tryring to install zorin 8 or lite, and can't get anything to happen. I downloaded a dvd and I bought one, neither works. I put the dvd in and boot the computer. usually, the dvd just turns and nothing happens. once or twice I got to the blue start screen, but could not go further. what am I doing wrong? thanks, Jim

Hi,

if you burnt the disk yourself, did you follow this advice?:

viewtopic.php?f=5&t=4771

Where did you purchase the other disk from?.

Further to Wolfman's advice, have you ever used one of these on your old Dell machine?

http://www.allsop.com/cleaning-/dvd-carbon-edge-pro-/