Plan for it. Baby, this is not a joke. It will break and it will fry. It will make you wail and cry. Your best and cheapest insurance is having good backups of your system.
Tape backups are inexpensive and easy to use.
When you buy a new computer, hang on to your old one as a spare computer. Then when your computer needs service, you will still be able to do your work. When you have a problem and need to call tech support, courtesy and preparation will get you much farther than being nasty. The people who answer the phone are lowly minions with no say in company policy. Their job is to route your call correctly and gather necessary information.