Why is my a drive not accessible?

My a drive says it is running in dos compatibility mode file, i have tried replacing the connection cables the actual drive and the power cable. when I replaced the actual drive it lit up but would not run or spin the floppy disk… and I would receive the error message “a drive is not ready” and give the options of try retry or cancel, retry does the same thing…when i looked in system properties i found my hard drives but according to it the floppy dosen’t even exist, i have also ran installnew hardware but it dosent detect it…What should i do?