What should I do?

Hi! I’ve re-formatted my windows 95
machine, and while trying to change my
drive letter to D: to re-install Windows I
received an “Invalid drive specification”
error-I re-started the machine, boots up
fine but after it detects the floppy drive I
get an error message “Invalid System
Disk- replace the disk, and then press
any key. Done that too-with all that I have
but I just can’t get pass this screen, any
suggestions would be greatly and kindly
appreciated. Thanks