Flash drives are a convenient way to transfer files form one PC to another.

But, in my experience, they are not as reliable as hard drives, so I would
not advise moving
files to a flash drive as the sole copy of the file.  Of course, you should
also not use a hard drive as the sole copy of any important file, since hard
drives can crash, and even short of that, files can go bad, or you could get
a virus.

Instead, write to a CD-R or DVD+-R (not CD-RW not DVD+-RW) for longer term
storage.

But, for temporary access, a USB 2.0 flash drive can be almost as fast as a
modern hard drive, and it is portable.  However, if your PC only supports
USB 1.1, then it might be painfully slow.

As for using a flash drive with windows 98SE, first download and install the
98SE drivers from the flash-drive maker's web site.  Then, plug in the drive
and it should be recognized.

Flash drives usually come pre-formatted as FAT32, which is compabible with
98, ME, XP, and even LINUX.

If you wish to format manually, then a right-click on the drive letter and
choose format.  Normally a quick format is sufficient.  But, perhaps the
first time you should do a long format.

In their normal usage, flash drives do not need to be defragmented.

Note:  If disk space is a problem, consider getting a larger disk.  These
are fairly cheap, especially in the sizes that are likely compatible with a
win98-based PC.  If the PC is a decktop, adding a second disk as a "slave"
drive is usually very easy.  If a laptop, then you would need to replace the
hard drive and transfer files.  Most retail hard drives come with a CD of
tools. including one to "clone" the old drive to the new, larger one.  Or,
any PC shop could do this for you.  Just be careful to avoid a disk too
large for your motherboard.  Staying under 32 Gig is probably reasonably
safe.  The near nearest common limits are at 8 Gig and 127 Gig, depending on
whether the motherboard is really old or fairly modern.  Note that most 40
Gig disks have an optional jumper to lower their effective size to 32 Gig.

I suggest that you don't defrag flash drives. Although they can be
erased and rewritten many thousands (?) of times, there is still some
limit to the number of writes. AIUI, the controller within the drive
continually relocates sectors (eg FATs) so that the same logical
sector is not always at the same physical location. This guarantees
that no sector is rewritten more often than any other, thus maximising
the life of the drive. Therefore, it stands to reason that, if the
drive's controller is continually relocating sectors, then trying to
do essentially the same thing with defrag will be pointless. In any
case a flash drive has no moving parts, so data accesses do not
involve slow mechanical seeks.

- Franc Zabkar