Virtualization of Microsoft Windows 9x systems is a bit problematic due to 2 major bugs: TLB invalidation bug and CPU speed limit bug.
This program contains a set of patches to fix these bugs, and can be booted from a floppy on a virtual machine. It either applies the patch to the installed system, or it patches the installation files in order to create (relatively) bug-free installation media.
A must-have for your Windows 95/98/ME virtual machines.
I tested it with Win98 SE, and while I was able to complete the installation, there are still random problems with stuff crashing, giving kernel.exe. I’d be willing to bet these are also related to the weird architectural differences that have crept into modern x86 processors.