i need help!

HI GUYS
I've tried to burn some xbox games by a DVD burner...

My DVD Burner is LG DVDRAM GSA-4160B(Internal super Multi DVD) Drive,
I am using Nero 6.6.0.1 Enterprise Edition
i am using DVD+R discs
My XBOX is upgraded (moded chip)

here are what I did:
the downloaded file was in rar format...i extract it by winrar..i got an iso file
i used Nero to burn the iso file as an amage
the speed was 4x

but when i put in the XBOX it gave me a message: " Your XBOX cannot recognize this disc. Mke sure it is XBOX game, DVD movie or Audio CD................."

I tried many discs many ways ...there is something wrong

a friend told me about the setting of a "book type" in the burning software which should be DVD-R when using DVD+R discs...I couldn't find where to fix that and i am not sure if this is the problem

another gut adviced me to patch the iso file by craxtion....i tried Craxtion to patch the downloaded iso file but it didn't work and gave an error messege "invalid file ! File to patch must be ISO ir XBE file!" ..it was an iso file..what's wrong with Craxtion?!
i tried craxtion to explore the iso file ...then to patch XBE within the explorer and it gave me a message.."files already patched"
-------------
same thing happened when i tried to burn a DVD movie ( downloaded or from original file)..i got the same error messege...

plz i need help...i spent a lot of money to buy the burner and upgrading my XBOX but i didn't get any advantage of it

Could anyone give the detailed procedures and the recommended software to use ... :idea:

thnx