If you have employees and computers, you might have computer problems. The combination is inevitable but the problems are not. Today, there is a war between people who want to hijack your computer, browser, e-mail box or Web site and your desire to keep your business focused on business. If you want to stay out of their way, you will need to impose some new restrictions on your workforce.

New rule No. 1: Do not allow employees to open e-mail attachments.

If you have no policy against, opening e-mail attachments or downloading software you might be in for a rude shock. When I mention this to small business owners they often say, "Oh, we NEVER open e-mail attachments." Sometimes the owner's attachment opening record is clean but the staff is opening anything that looks vaguely interesting. I have worked with one staffer who opened attachments which introduced the same virus into her computer twice in one week.

Yes, there are exceptions. Perhaps you are waiting for a photograph from your PR firm. If you get a .jpg from those people you are probably safe in opening the file. If you aren't expecting the file, though, it is time to call the sender to be sure you aren't getting into trouble. You do have your up-to-date antivirus program scanning your e-mail, right?

New rule No. 2: Do not allow employees to download unapproved software onto your system.

The problem with the e-mail attachments we were just discussing is that they may be executable files. Well, we know that downloaded software contains executable files. The toss up is whether or not the person who wrote that program means to harm your computer. You don't trust everyone you meet on the street, do you? Then don't trust everyone you meet online, especially if they want to run their software on your computer. Random downloading is not a safe practice.

One recent form of spyware masquerades as a search engine toolbar. Other programs hijack your browser and force you to go to certain websites. Still others record your online activities or use your computer to generate spam or to launch denial of service attacks. Some of these intruders cannot be corrected even by antivirus or anti-spyware. You might need to take slower and more annoying steps to get your system back to normal.

New rule No. 3: Do not allow employees to leave fully functional workstations unattended.

Do you want clients, passersby or even other employees to be able see the entire contents of every computer's hard drive? Then, it is critical that you protect unattended computers. I often ask employers if they have their payroll records and financial statements cordoned off from the rest of the network or, at least, protected by strong passwords. Often, the answer is no. A good rule of thumb is not to leave the data on your network open to snoopers unless you would be willing to print the information and tape it to the water cooler.

Recently, I consulted with a small firm owner who had noticed malfunctions in his e-mail software. Someone had made changes to Outlook Express, evidently while trying to check their own e-mail account. I found a few other small changes including the tracks of some Web searches for information about a contest run by a cigarette company. Since none of the employees smoke, it was reasonable to assume that an outsider had been tampering with the workstations. It turned out that the night cleaning crew had been using the computers when no one was around.

One way to prevent this problem in XP is to logout of your user account when leaving the workstation. You can switch to a guest account without administrative privileges and return to your own password-protected account when you return to your desk. A tool that was written for Windows operating systems prior to XP is called System Lock. It does just what it says. When you launch the program it locks the computer until you return to your desk and enter your password. Just be sure that you remember the password you set or you might end up protecting your computer from yourself.

No set of rules can keep you safe from an occasional error. But, if you let your employees know how you expect them to treat your workstations, you'll have fewer disruptions due to computer problems in your workplace.

Alan Thornton owns Decatur Computer Help, an on site technical support business in the Atlanta area. Write him at alan@decaturcomputerhelp.com.