The 3 1/2" floppy has had a long run of popularity, but its use is fading.
It is sensitive to dirt, magnetism, and mistreatment. Make sure the sliding dust shutter fits tightly and operates smoothly. If it is at all bent (or, worse yet, missing!), bring it to WRC staff, and we'll "diagnose" it for you.
There is a very small "drive active" light on the computer. If you accidentally eject the disk while the light is on, the computer may refuse to read anything from the disk. In this case, bring it to WRC staff, and we'll "diagnose" it for you, using our "Disk Doctor" program.