No need to re-format unless you want a clean drive.

Hooking up a 2nd drive to anywhere but the Master slot on the Primary IDE controller will keep it from being assigned drive C.

Once the new drive is installed, boot to the BIOS settings to make sure the BIOS sees the new drive.

I think WinXP might let you use any drive for the boot drive & will recognize where the OS is located. I think WinXP might even let you change drive C to another letter and it should still boot. I don't see any reason why you would want to do this, but XP lets you do it. XP won't complain, but I'm sure any application you've installed to drive C will complain.

In WinXP, to change the drive letters go to Control Panel -> Admin Tools -> Computer Management -> Disk Management (on the left). Right-click on any partitioned drive (in the top or bottom window on the right) and it will give you the option of changing drive letters.

The added drive will still have the OS on it, which is safe to delete and anything in the Program Files folder will be useless unless you re-install the application onto the new drive.

You should be able to plug it in as D: and go--I did that with mine and Nic's computers. There are a few things you have to look out for, though.

In standard IDE/parallel ATA configurations, the boot drive is designated the "master" while the secondary is designated "slave," except in California, and you can probably figure out *that* Charlie Foxtrot. It's usually just a jumper setting, and most drives have the appropriate settings documented on the drive label itself. In other words, you might have to change jumpers on the secondary drive (Mrs. Ted's drive). Sometimes the cable does the selecting for you.

Take a look at the primary drive (yours) and the jumper settings and compare them to what the label says: If it looks like it's set for Computer Select (AKA "CS") set Mrs. Ted's drive for CS. If yours is set for Master, set hers for Slave, and I don't need to know what you're thinking.

Also, some computers have a data cable that only accepts one drive, and that's a whole other headache in that you have to get a new cable. The chipset should not be a problem, though.

New computers (last nine months or so) might use a new technology called Serial ATA, which uses different signal/data cables completely, and usually a different power supply connector as well. The data cable is narrower than the current 36-pin cable; the drives are not compatible. Some computers allow both types of drives, though.

Thanks guys. I've installed a hard drive or three over the years and knew about the master/slave thing, or at least enough to look for it. Mookie has a bud who's one of Best Buy's Geek Squad and he's volunteered to check the drive and retrieve the data from it. He thinks Liz caught a virus way back and it finally overwrote the backup cache or something. This problem with her PC has been intermittent for almost a year.

I doubt it is the motherboard. I think your geek friend is right. Or perhaps a sector opened on that new drive or the read/write head is crapped out. Generally when I get an "Operating system not found" it means the bios is doing it's thing but the hard drive is not spinning (ie no lookie for OS). Verify that the drive is actually spooling up and spinning plates before you go to a bunch of trouble, or that it is not making an obviously wrong noise. Retrieve the data if you can by terminating it or slaving it as D in another machine, then you can shove it back in Liz's computer and do a clean reformat. Blow all the partitions and data off and you shouldn't have a problem.

It's the way of the windows brah. Reformat once a year or so. You can set your watch by it.

I'm with bitterman on the reformatting once a year thing. Instructions always warn you that it's an all-day affair, but whenever I reformat, I'm usually back online and have my favorite programs installed within about two hours or so, start to finish. Then again, I only have a 7 gig harddrive. Don't know if that matters or not.