try setting the hdd to 'cable select' instead of master or slave thats what i use for my removable drive for collage, only way it shows up on their machines, dont have to worry about changing it when i get home either.
Your problem is that you can't use that 100 gig drive that already has the OS on it on your carputer. As Skippman said, your computers have to be EXACTLY alike or you will get that blue screen. Now that you have switched out the hard drives and put them back, it seems like you have corrupted the files and possibly the registry. I recommend backing up everything on another computer that works and format all your drives. I had a similar situation occur with hotswapping my removable drive but mine didn't ruin my OS. It just blew out my sound card.
So just be careful when swapping that stuff out.
Only XP/2K/NT will give you the blue screen problem. Win9x will simply redetect hardware. You will end up with a mess, but it'll run well enough for you to clean out the device manager properly.
Really, to switch a 9x drive to another system:
-install drive in new system
-boot into DOS w/CD-ROM support
-copy CAB files if not already there
-reboot, go into safe mode
-run regedit, delete HKEY_LOCAL_MACHINE\Enum (clears hardware)
-Windows will redetect all hardware. Have drivers handy
Works everytime for 9x systems.
Player: Pentium 166MMX, Amptron 598LMR MB w/onboard Sound, Video, LAN, 10.2 Gig Fujitsu Laptop HD, Arise 865 DC-DC Converter, Lexan Case, Custom Software w/Voice Interface, MS Access Based Playlists
Car: 1986 Mazda RX-7 Turbo (highly modded), 1978 RX-7 Beater (Dead, parting out), 2001 Honda Insight
"If one more body-kitted, cut-spring-lowered, farty-exhausted Civic revs on me at an intersection, I swear I'm going to get out of my car and cram their ridiculous double-decker aluminium wing firmly up their rump."