If not, it should be, and quickly-and not just in one place either. I got a hard lesson in that this week. The hard drive on my main business PC died. I had two backups-one on the PC's secondary hard drive and one on a usb stick. I also had other data such as pictures and mp3's backed up on CDs. The importance of having more than one backup was made crystal clear to me when the back up on the second hard drive ended up being corrupt. Fortunately the usb stick worked just fine, and the loss of data turned out to be quite minimal.

Relying on the System Restore feature built into Windows? Don't. Not one will it be absolutely useless if your hard drive fails, but if you need to restore your system due to a corrupt program installation, or even worse, a malware infection, the restore points will be affected to. Always do regular back ups (I recommend one a week) to a flash drive. CDs will do, but flash drives are more durable and longer lasting. Make more than one copy of your backup and store one somewhere outside your office such as a safe deposit box. I keep a copy of my backups in a fireproof box in my home and one at a relatives house. You simply can't be too careful. Now go back up that data!