Badpolorbear has it right.
Anything over 40 gig is really OS specific. you can fat32 format a drive with the UPDATED windows format command--I did a 100 gig--going over 64 gig shows error on the format, it will subtract 83 gig from your 100 gig drive and tell you its formating a 17 gig drive No problem though you have access to the full 100 gig. The problem starts when you interact with a third party program like Perfectdisk (a defragger). you'll find your OS parking out in La La Land for no reason or worse. The Microsoft documentation says that over 64 gig is "undocumented."
You'll notice that XP will not give you the fat32 option on an install with drives over 40 gig. You have to go in and format it yourself if you want to go that route. Fat 32 is neat and very forgiving if you want to floppy drive boot and get into the hard drive. NTFS ain't going to work that way--three floppys and you still might be knocking on the door.
Then here comes another problem. The IDE interface is 32 bit for older motherboards. So if you have a 32bit IDE motherboard, it will not see a 160 it will see 139. At this point you need to either upgrade your motherboard or add a 48bit IDE card to the system. That will put you somewhere into 2 tetrabytes.
Here's where the fun comes in. If you bought a computer with windows 98 on it 5 years ago and tell me you want me to install the new 160 gig hard drive you just bought, it might not reconize more that 20 gig. I believe Wjindows 98 ME and XP support up to 64 gig on fat32, but from there, your in there with Captain Kirk and the Starship Enterprise---where no man has gone before
