Your computer and any program on it can abruptly cease functioning at any time. If that happens, it may be possible to go back to your last good backup and redo everything from that point. In our office, we have automatic backups set up to run every few minutes. But those backups, of course, are just going to another computer in the same building. Several services offer backups to a server in another city. That can get to be expensive for a small user.

For even a relatively large database, it is possible to backup to a small device and carry it to a computer in another building. A USB flash drive, stick memory, thumbdrive, (different names for the same thing) is convenient. Some companies ban them. Although I consider a ban throwing the baby out with the bath water, you do need to take at least two precautions as outlined below. I realize that in a big company, it is hard to get everyone to be careful. If you are unsure of the precautions or if you are in a company that bans thumbdrives, you could use CD-Rs or DVD-Rs. Thumbdrives are cheap and reusable, but CD-Rs also cost little.

Moreover, you can get USB hard drives large enough to make images of your computer (the whole thing), and they are almost as convenient as a thumbdrive. In the US, they cost less than $100 at Wal-Mart. Western Digital makes "Passport" drives that are about the size of a passport. They make you run a program when you attach one. You can assign a password. After that, you only need to connect the drive, open the partition with the programs (it appears as a CD drive), and run the Unlock.exe program. If you get a bad virus, it can disable safe mode and restore points. That image may be your only hope. Go to Control panel / backup and restore to make one. One of my PCs has over 40 Gbytes of data and takes about an hour and a half to complete an image. The other part, the system repair disc that recovers the image, goes on a CD-R and can be created in a few minutes.

You can copy the thumbdrive data onto another computer at another location in case of catastrophe. It's also nice to keep just a bit of old backup data. Your January data was fine last February, but now in September last January is screwed up. What changed? In QuickBooks and Peachtree, you have an audit trail report IF the history has not been condensed. If you have a historical backup, it is far easier. You can print reports and compare them line by line.

Both Peachtree and QuickBooks will sell you backups onto their servers. QB's currently starts at $5 a month (an 8Gb thumbdrive is like $15, and it will last a very long time). PT includes a basic free backup service. A small office is not likely to get out of the free (100Mb) range. But if you do, the subscription prices are suddenly very significant. A 16Gb thumbdrive, 160x the 100Mb range, is still inexpensive - less than $2 per Gb. (Note that same Gb costs $50/year on Intuit's servers.) I have known two people who trusted companies (not QB nor PT) to keep backups on their servers only to discover one terrible day the servers were wiped out. And the companies themselves had no backup. The companies claimed they were not liable.

There are two precautions you need to take with thumbdrives. They attach to your key chain. Indeed, you'd be wise to fasten it securely to your car key so you won't go anywhere without it. But you could still wind up with all of this private data for anyone to find lying in the parking lot. You can solve that by encrypting the data. I use TrueCrypt. The price is certainly right, currently zero, and it is easy to use.

The second precaution leaves me feeling a bit down as it ruins a lot of the potential value of a thumbdrive. In theory, you should be able to load accounting software and data onto a thumbdrive, insert it into any computer, and pick up where you left off at your last location. The problem is that if you run ANY program off of a thumbdrive or any other removable media, you could insert a virus onto the host computer. Note the default even as of Windows 7 (you can change it in autoplay options in the control panel) is to automatically run an initializing program if one exists every time removable media is inserted. Thumbdrives arrive with such programs. Some thumbdrives even come with encryption programs already on them. I think it better to use them strictly for data storage.

When you insert your thumbdrive, it is mere caution to scan it for viruses. Malwarebytes is a good free program to do this. Right-click the thumbdrive, and you'll be given a choice to scan it. Kaspersky (not free) offers to scan it. The problem is that an encrypted volume is also hidden from virus-checking software. You have to open it first, and then scan it separately. Kaspersky apparently cannot scan an encrypted Truecrypt volume that has been opened. Bug, I guess. I take every precaution. Right now, I'm very gun shy.

I'd like to think I'm reasonably careful and experienced, yet I got a vicious virus on one of my computers running Windows XP. I wasn't visiting some "naughty" web site, (but not exactly a business site either). I don't watch many videos and had dismissed irritating requests for Flash updates. Well, Flash ran an ad on the side of the screen. It broke, and a Vundo variant went in through a crack. I suddenly started getting ads for "Personal Defender" purporting to be a virus removal tool. It WAS a virus. I could not boot into safe mode (usually you do that by tapping F8 right after turning the machine on). I could not use system restore nor any of the other tricks. All of those avenues had been blocked.

I put the hard drive on another computer and scanned it with Malwarebytes and PC Tools. That took hours and located 100 instances of malware. When I put the drive back into its original computer, booted up and did a scan, I still had a virus. It was a rootkit - a virus inserted directly into the system where it could be activated upon bootup. I think I still could have removed it using ComboFix (freeware). But I became afraid of XP (and Flash, but there is no way to avoid Flash). I just did a reinstall. Everything was backed up elsewhere. Then I upgraded to Windows 7.

Very recently, I have had two people tell me their credit card numbers had been compromised. A virus doesn't have to be obvious.

Have a backup plan before you even start with an accounting program. And dadgummit, make sure you can actually open that backup on the other computer. This is no time for false security.