I've been working on and off for months now on a dual-video card, multi-boot system that will include DOS, Windows 98, Windows XP, and Windows 7. I've managed to fix most of my problems (mostly resource conflict issues) and have each individual OS working how I want, but one lingering problem remains that I just can't figure out - my floppy drive. When booted to a command prompt (Windows 98's DOS), changing drive to letter A results in an "invalid drive specification." And within Windows 98 itself, the A-drive is visible, but double-clicking on it leads to floppy drive activity, then after a few seconds it always spits out a disk-not-formatted error. From within Windows XP and 7, the floppy drive works properly.

Interestingly enough, the floppy works fine in 98 and DOS on this same exact hardware with the same exact BIOS configuration when just 98 is installed, or even 98 and XP. It is after I install Windows 7 that the problem arises. I thought maybe it was the number of partitions or something like that, but even deleting Windows 7's partition after the problem arises does not fix the problem. As best I can tell, it is something with Windows 7's boot loader that is breaking this. Either that, or EasyBCD.

Any ideas here as to what exactly is going on?