Nothing elicits such a strong case of technology guilt as asking other people if they back up their computers. Eyes dart toward the ground. Excuses are made. The subject is quickly changed.

As many people know or quickly find out, backing up a computer can be a painfully slow process. This week, I tested a computer-backup system that requires minimal effort and works in the background to automatically back up files: CrashPlan. This appropriately named program is made by Code 42 Software, a Minneapolis-based company.

CrashPlan works with all types of operating systems and lets users back up to remote servers in the cloud and/or other computers or hard drives, like another PC they own or one belonging to a good friend or family member (as long as they give permission). The system also sets no restrictions on file size.

On a typical home Internet connection, the backup process to a CrashPlan remote server could take several days or even weeks for a first-time backup. (After that, backups are much faster and happen unnoticed.) The first-time backup for one of my laptops with about 46 gigabytes of data had been running almost continuously for three days when I filed this column on Tuesday. After the initial backup, regular backups won't take nearly as long. CrashPlan has a mobile app that works on Apple's iPad, iPhone and iPod touch, Android and Windows Phone 7, allowing remoteaccess to backed-up files.

The free version of CrashPlan enables a daily backup to other computers and hard drives but not to Code 42's remote servers. The subscription-based CrashPlan+ will back up to the remote servers as well as other computers or hard drives. It can back up as often as once a minute and lets users choose what data to back up where.

CrashPlan+ comes in three payment plans, each with its own tiered rates