OK, here is the first thing you need to do.
Of course DL memtest86 and then add it to your floppy, etc. (can't see whats in it since it is a bootable floppy now)
As soon as you restart your comp access your BIOS and go into the BIOS settings and change it so that your comp boots up the floppy as it's first primary drive instead of your harddrive, etc.
Memtest should then work fine (don't forget to change back the BIOS setting after you are done).
This is what I did for my system, just my $0.02