Taking backups is the most important regular procedure for any computer user with valuable personal data, so you need to work out a backup strategy. If you don’t take backups, and end up losing data as a result, I might still be able to help you recover, but the sensible thing to do is not rely on that!
Some people back up data from one partition of a hard disk onto another partition of the same disk, but this method is almost useless. The whole idea of a backup is to make a safe copy of data in case of loss, but if the hard disk containing the two partitions fails, you end up losing the partition containing the original data and the partition containing the backup.
A better method is to have two hard disks inside the same computer, then work on one disk and back up this disk onto the other one. Many computers can operate a system called RAID where the contents of one hard disk is continually mirrored by another identical disk. However, if the computer is stolen, or totally destroyed, once again your backup has gone the same way as the original data.
One of the best ways of backing up a hard disk is onto an external hard disk drive which is usually stored in completely different premises. The problem is going back and forth between your place and the other location where the external hard disk is normally stored, because you’ll need to retrieve the external hard disk every time you want to make another backup. In real life, people often back up their data onto an external hard disk then keep it in the same building as the computer, but not in the exact same place.
Another very good way of backing up a hard disk is onto optical media, such as CD-ROMs or DVDs. These are small and light, and you can always get a friend to keep them for you on their premises as they won’t take up much room. In return, you can keep their backup media on your premises. If you’re worried about sensitive material falling into the wrong hands, you can always encrypt it. So long as you use strong encryption, the optical media backups will be useless to anyone except you. By the way, you really should use ‘archive quality’ media, as some run-of-the-mill optical media are of variable quality (that’s a polite way of putting it).
The capacities of USB flash memory drives are increasing all the time, and the prices keep on falling. It’s now practical to back up small datasets onto 16 GB, 32 GB, or 64 GB flash memory drives on a daily basis. After working on very important files, I back them up onto USB flash memory drives at the end of the day without fail. However, the long-term stability of flash memory is uncertain, so I copy material from one flash memory device to another every so often, just to ‘refresh’ the data.
A really smart solution is to back up your system onto servers that are on the Internet. It’s highly unlikely that any problem affecting your computer will also affect these servers, and they will be administered by professionals. You can also access the servers from almost anywhere over the Internet. However, if the information held on your computer is sensitive material, you may not want it being copied to who-knows-where. One solution to this sensitivity problem is to keep all of the data on your computer encrypted, so the backups on the Internet servers will be useless to anyone but you. The problem with encryption, though, is that determined people can often crack weak systems, so the only truly effective encryption is the kind that uses the strongest and latest techniques. Also you need to bear in mind that if your Internet connection goes down, you’ll temporarily lose access to the backup servers.
The ultimate way of making sure you never lose any data if your computer breaks, or is destroyed or stolen, is never to keep any data on it in the first place. There’s a way of working called ‘cloud computing’ where all your files are out there somewhere on the Internet (‘in the Cloud’) instead of on your computer. Your files are distributed all over the place on other people’s servers, and hopefully they back them up. You just access them when the need arises, and in the meantime someone else should be making sure that they’re kept safe. Like a lot of things, this is not a new idea, but is promoted as if it were. You need to bear in mind that with some ‘cloud’ services, there are terms and conditions that you’ll probably find disagreeable. Organisations running ‘cloud’ services often disclaim responsibility for disasters, so you might want to look for one that’ll compensate you properly if everything goes wrong. Good luck with that.
There’s no point constantly backing up data that doesn’t change, such as Windows itself, programs for which you have CDs, programs that you can easily re-install by downloading them from the Internet, and so on.
Taking full backups all the time is unnecessarily time-consuming. The best way to take backups is to do a full backup from time to time, and only incremental backups in between full backups. An incremental backup is a backup of just the files that’ve changed since the previous full or incremental backup, in other words just those things that’ve altered and not yet been copied to some other device for safety.