My friend's box is at the moment unusable due to a dead hard drive, and he used to use live. Now, assuming I got a new hard drive in there for him, would it be possible to just simply change a few values in ConfigMagic for his old EEPROM to create a new 'virgin' EEPROM which would be slightly different? And if I tried this, what values would I want to change? Has anyone tried this?

I'm thinking that if you changed the serial number, mac, online key and unique hdd key, that is just as good as a virgin eeprom, correct?

Anybody agree or disagree to whether this would work or not?

No it will not work
the Online Key is like a windows key you can't just make one up
and if you do XBL will report " there's a configuration problem with your xbox " and not let you in..

oh really, thanks for the reply, I guess that makes sense that they would do that.. I was just hoping I wouldn't have to purchase a new EEPROM but I guess that's my last resort.