From OP:The title is booting failure
It is wise to read the full thread before making a reply, if only to ensure you aren't repeating advice of others- it's also useful to prevent posting in a 2 year old thread (This one is fairly old). Even so, the OP has responded and basically brought things back to the original issue.
Somehow this got wally bugled to Windows 98 reading a flash drive.
Well the original consensus was that the hard drive was failing and it was a good idea to get all the important data off the drive before it fails, which is where the USB drive came i, and the issues using it with Windows 98.
A bookable Flash drive can start widows 98 hard drive having boot issues.
This is a Windows 98-Era PC. Mass Storage devices weren't even ubiquitous enough to bother creating USB Class drivers for them, and they certainly couldn't boot from USB Drives at the time either.
Basically, the issue is that the drive was failing, and they had issues getting the flash drive to work originally and just left it be- Now they want some documents from that computer and the hard drive has gone from failing to failed.
I think the best option is to hook it up to an enclosure and connect it to the more modern machine. hopefully the drive is still accessible. It's likely the drive is completely hooped at this point though.