Usually, most floppy drive (most often called the A: drive) problems are due to the disk and not the drive itself. To check whether it is the drive or the disk, try another disk. With the disk that is causing problems try gently sliding back the metal cover a few times, letting it snap closed again. Don't touch the actual magnetic surface inside.

If you get a message the "A: drive is not accessible" check that the disk has been inserted properly. Are you sure that the disk has been formatted?

Sometimes the cause of the problem could be that the read/write heads of the drive are dirty. Special cleaning disks can be obtained from computer stores.

If you get a message "Invalid drive" it means that the computer does not recognise the presence of the floppy drive. This could be caused by:

1. The ribbon connector to the drive becoming dislodged
2. The floppy drive controller on the motherboard has malfunctioned
3. The CMOS settings are wrong