See the econ computer consultant if you have a reasonable need for more space. Disks do fail and when they do, the files saved on them will be gone. Nearly every week I see a student who has lost some work due to a diskette failure. Floppy diskettes are the least reliable, hard disks are safer but not certain. To protect your work keep at least two copies of your important files.
Computers can and often do crash or freeze up.
Every 10 minutes is reasonable.