Helping people with computers... one answer at a time.
Usually you can take the internal hard disk of an old computer and install it as an additional drive in a new one. There's a more flexible alternative.
The good news is that a working hard disk that was formatted for use by any prior versions of Windows can certainly be read by Windows versions that come later. Your Win 98 disk can be read by Windows XP and later, and Windows XP disks are readable by Windows Vista and Windows 7.
The not-so-bad news is that you'll have to open the box, extract the drive, and do something with it.
I'll admit it: That's not for everyone.
It's actually a common approach used by computer geeks ... take an old hard drive from an old computer and install it as the second drive in a new one. Everything that used to appear on drive "C:" on the old computer might now appear as drive "D:" on the new one. Once it's set up, copying files from old to new is both easy and fast.
And this approach comes with a bonus. Once you're done copying the files you want to keep, you can leave the old hard drive in the new machine, reformat it if you like, and have that much extra disk space to use as you like.
The down side is that you need to be somewhat computer hardware literate to install the drive. It does mean opening up your PC and connecting the old drive in the right way in the right place. There's no "one way" to do it - it can vary based on the type of computer you have and the type of hard disk.
A more flexible approach is to instead take the old drive out of the old computer and install it into an external USB drive enclosure.
That's basically all that most external USB drives are: common hard drives in an enclosure that provides power and a circuit board to provide the USB-to-hard drive interface.
There are two things that you need to know before purchasing an external USB enclosure:
The drive size.
By size in this case, I mean the physical size of the drive. The external enclosure that you might select needs to match the physical size of the drive that you're about to put in it.
There are two primary disk interfaces these days: SATA (on the left, above) and IDE (on the right). Most newer drives are SATA, but particularly on older machines, you're likely to run into IDE. The external drive enclosure that you get must match the drive: SATA or IDE.
Once you've installed the drive in the appropriate type of enclosure, all that you need to is connect it via USB to any computer (and perhaps to power) and you'll be able to access the data on it.
Regardless of whether you install the hard disk in a different computer, or install it into an external enclosure, you will need to be comfortable opening up the old computer, disconnecting, and removing the drive. Then, depending on your choice, you'll need to be prepared to install the drive in its new home.
If that sounds like too much, then perhaps it's time to find a technician or at least a techy friend.
It's typically a fairly quick and easy operation for someone that knows what they're doing.
(This is an update to an article originally published September 19, 2005.)