Not all Windows 98se CDs were bootable. Back then you would use a DOS diskette and edit the usual config.sys to load the driver for the CD drive then MSCDEX in the autoexec.bat file.
But since all that is on the internet I don't duplicate that here.
What I find are folk that can't edit text files so for those folk maybe Linux would be a good choice to install and run on old gear as it does install without having to use the old ways.
I was given a Gateway Solo 5150 laptop with a "designed for Windows 95" sticker. It's a Pentium II, 4GB HD, and originally 32MB RAM. It showed a Windows 98 spash screen but wouldn't boot due to a missing/damaged VMM32.VXD file. Long story, but couldn't get it working, so I connected the HD to another computer via a USB adapter, deleted the second 2GB partition, formatted, and looked to start anew. I added a pair of 256MB memory sticks but BIOS only sees 64MB of each, plus the original onboard 32MB. No big deal?
I'm looking to get a Windows 98SE install disk. Question 1- does the Windows 98SE install process work like newer OSs, meaning boot from the CD and install? Question 2 - thinking about drivers, internet connection (only has a phone line port), etc., would I be better off installing Windows 2000? I have an adapter card for an ethernet line.
I can see this could be a big can-of-worms and I don't want to put much money into it. For instance, I have no intention of looking for a new battery, but I'd have to dig into it to replace the MB coin-cell battery. I'm obviously having second thought about this project. If I get going, I can envision many more questions coming up.