A Formatting Problem

I have followed the instructions to the letter using the Dell supplied re-installation DVD for XP Media Centre version. Changed the boot order to CD/Floppy/HDD etc.( have put the re-installation DVD in the DVD player & CD player), but when I try to boot up I get a black screen with white lettering saying, "Select F1 to re-try boot up or select F2 for set up ", doesn't matter how many times I try F1 it just repeats the instruction down the Page, "Select F1 etc. etc. "
Yes, I did lend the DVD to a 'friend' and he then told me he had copied it! Not sure if this has any bearing though? Dell Dimension 8100.

Any ideas much appreciated.
regards,
Stuart.

 

Thanks Tony, all now sorted.