As with any system work, you back up important data in case something goes
wrong.  When things go right as they do 99.9% of the time, no files are
lost.  If you don't have enough hard drive space, the installer will not
begin.  A typical upgrade from Windows 95 requires approximately 195 MB of
free hard disk space, but the hard disk space may range from between 120 MB
and 295 MB, depending on your computer configuration and the options that
you choose to install.  20 mb of ram and a 486/66 CPU are required.  W98SE
is the version you should use.

Go to http://www.pricewatch.com, click on the software button and then
search on:  win98.  They have listings on boot up floppy disks, CDs but no
license, a license but no CD, OEM, W98, W98SE, update from W98 to W98SE only
and so on.  Pay ATTENTION to what the listings say or you may end up with
something you don't want or need.  You can also check on EBay or other
auction sites.  You also need to be aware that only paid support for W98
still exists.  Here's some info about the various types of W98SE CDs:

RETAIL FULL INSTALL:  This CD will either upgrade W95/98 to SE or you can
install it to a blank hard drive.

RETAIL UPGRADE INSTALL:  This CD will either upgrade W95/98 to SE or you can
install it to a blank hard drive; however, when installing to a blank drive,
install will ask to see the qualifying system (i.e., W95) disk(s).

OEM FULL INSTALL.  This SE CD is designed to be installed to a blank hard
drive; however, there is a possibility that you can trick it into upgrading.
For info, go to:  http://home.satx.rr.com/badour/html/upgrade.html  Be aware
that if you buy an OEM disk, it might be customized for installation on a
particular computer; however, this will probably be primarily with a used
disk.

UPDATE CD:  This CD will only update a functioning copy of W98 to W98SE.
When MS sold them, they were $20 and came with a ProductKey.  Some venders
were selling them and advising customers to use the W98 ProductKey which may
or may not work--don't get stung.

RECOVERY CD:  Some companies will brand an OEM CD and call it a recovery CD.
You should avoid these unless it is the exact recovery CD you are looking
for.  Many recovery CDs will only install on the equipment they were
intended for.