"Plan B" is your technology backup plan.
Be sure you have one before you begin your online courses. Find a friend, a relative, or a public library that has a computer with Internet service that you can use in case of emergencies. Be sure it has any special software your course requires, software such as Microsoft Word or Excel. The Student Computing Lab and Helpdesk  on our Queensbury campus is available for your use. The SUNY Adirondack Wilton site near Saratoga Springs also has an open computer lab. . If you are a student at another institution, check out the student computing facilities available to you on your own campus.
"The computer ate my homework . . ."
At the end of every work session, save copies of your homework files to a flash drive, DVD, CD, or other portable storage medium/location. If the only copy of your homework is on your computer's hard drive and your computer dies, you've just lost all your work.
The key here is to not rely on one computer or one location in case something goes wrong. It is best to backup your work on portable storage devices that can be used at multiple location in the event of problem at any given location or computer.