if i were you i'd keep trying to hotswap since theres nothing else you can do unless you get them a modchip and a new hard drive.
heres some pointers:
-are you sure you're pausing the computer as its scanning for the hard drive?
-are you unplugging the IDE cord from the HDD at the error screen? [it doesn't matter when as long as its after the 'clicks'
-is the video cord plugged in which allows the HDD to unlock?