Ok, well here's some more tips:
#1 your drive is unlocked as soonas the MS logo appears, it just doesn't like t be swapped while transerring data, so just wait till everything has bootted up, about 10seconds is plenty
#2 run the hd power from your xbox, as long as the drive still has power it will not lock, you can reboot your pc numerous times. when it is first unlocked the drive is programmed to automatically lock when it powers down. for example, what i often do is hotswap in windows, if it doesn't work i just reboot, is the hotswap worked the time will still be unlocked when windows starts up again.
#3 sometimes windows will disable the ide cable when you try to htswap with windows running, if it doesn't work after a couple tries, try rebooting your pc and pausing it at some point, then hot swap and resume booting
#4 windows 2000 seems to work better sometimes, other times it's winXP, i have dual boot
#5 windows xp pro does not like to be hotswapped with windows running, but 2000 is ok
#6 always unplug your cd/dvd drives and use this IDE cable, it makes life much easier, trust me
#7 "scan for new hardware" is completely unnecessary, hotswap and launch hd driver, if it worked it'll be there
#8 if all else fails you can try detting your pc hd as slave, plug you xbox hd into the same ide cable and set your bios to boot from the slave.
#9 when you finally do get hddriver you might not see any folders, or maybe just one, sometimes you're lucky and can see them all. there tutorials on fixing this, it's easy.
this might sound complicated, but i've never ran into a hradrive i couldn't hotswap, 15minutes tops,