mate I have read a dozen guides including yours but still it wont boot.
I know what the errors are I need to get it to boot just once so I can reset the clock the reason I get error 5 after putting the other hdd in is because it HAS to be unlocked to work in another box

SO if the box then says error 5 its because the mod is not working and it is trying to boot a retail bios which will give error 5 coz hdd is unlocked.
If im missing something please explain a little more
Thanks for the reply BTW
PS its not really a newbies step by step guide from the start that i need as this Xbox has been working for over 9 months with the said mod in it and just all of a sudden it gave error 16 wasnt even unplugged or anything ??????
OH and PPS your tutourial doesnt even cover an error 16 scenario!!!!!!!!