Helping people with computers... one answer at a time.
Backing up your computer is an important step to avoiding data loss. We'll look at what it is, and give a suggestion for average users.
How do I "back up" my computer? I am sure my question is ridiculous to you but I honestly have no clue what I should be doing.
Your question's not ridiculous at all, and in fact I'm certain that one reason so many people don't back up is exactly that: they don't know how.
Let's first look at what it means to back up a computer, what your options are, and then what I typically recommend for average users.
Backing up is simply making a copy of program files and/or data, and then keeping that copy in a safe place. Nothing more, nothing less.
The goal of a backup is also simple: if something ever happens to your computer such that you can no longer get your information off of it (which happens more often than people realize), then you can always get the information from the backup copies.
Where backing up can start to seem complicated is when you look at all the options relating to how much to back up, how often, and the various tools to make sure that it happens regularly.
Backing up typically takes one of two forms:
Copying your data. This is conceptually very simple. For example, if you copy pictures off of your digital camera, and then immediately burn those pictures to a CD for safe-keeping, you've backed them up. Similarly, if you regularly take the contents of your "My Documents" folder tree and copy it to another machine or burn it to CD, that's one form of backing those files up; they're safely stored in another location in addition to the original.
Imaging your system. This is also conceptually very simple: rather than backing up only this-and-that, hoping that you actually remembered to include everything you might need in case of a disaster, this approach makes a copy of everything; your data, your programs, your settings - even the operating system itself.
Both types of backups share a common characteristic: whatever they backup, be it just certain files and folders or absolutely everything, they do so by a) making a copy, and then b) placing that copy somewhere else.
If your data is in only one place, and there are no copies, then you're not backed up.
So where should "somewhere else" be?
Well, the ideal answer is "as far away from your computer as practical". The further away, the more you are protected from various types of disasters.
If the backup is on the same hard disk, then if that hard disk dies you could lose your data and your backup.
If the backup is on a different hard disk but inside the same computer, then if something happens to the computer that causes the hard disks to be harmed, you could lose your data and your backup.
If the backup is on an external hard disk but connected to the same computer, then if there's a software glitch on that computer that starts destroying files on all connected devices, you could lose your data and your backup.
If the backup is on a different computer on the same network, then a network problem or virus on your local network could start deleting files and you could lose your data and your backup.
If the backup is burned to a CD or DVD but kept in the same location, or any of the solutions above are all in the same location, then if that location suffers a physical catastrophe such as a fire or flood you could lose your data and your backup.
That's kinda scary stuff, but you get the idea. The closer your backup is to the original data, the greater the possibility that you could lose both at once.
All that can seem pretty overwhelming, but so far the take-away is simply that backing up is making a copy of your data and storing it in a safe place away from your computer.
The question that remains, then, is just how should we do that? The questions that drive that answer is just how likely are those problems I've talked about, and how important is the data?
The more important the data, the more frequently you'll want to back up, and the more copies of those backups you'll want to keep in various locations. The importance of your data is something that only you can really judge.
By far the most common issue that I see people encountering that causes data loss is hard drive failure. OK, hard drive failure and accidental deletion. In my opinion a great place to start is to protect yourself against at least those.
There are many approaches to backing up, which I've discussed in an earlier article What backup program should I use? Rather then revisit those approaches here, I'll make a simple suggestion.
For most average home users, I suggest:
Getting an external USB hard disk.
Using an automated backup program like Macrium Reflect or an equivalent, and backing up to the external drive automatically on a daily or weekly schedule.
This won't protect you from everything, like your house burning down, but it will protect from what I see are the most common causes of data loss. If your hard disk dies, you can restore files, and perhaps the entire system, from your backup. If you happen to - oops! - delete a file by accident, then as long as it was there when the most recent backup was take, you can restore it quickly and easily.
There's no general "how to" that I can provide here that would cover all the different backup programs you might try, but the good news is that most come with relatively simple instructions to set up the most common types of backups for average users.
As your needs increase, as you determine that the importance of your data requires stronger measures, then you'll have a good base to build on.