The oldest rule of medicine is “first do no harm.” It’s much the same with computers. Today I’ll tiptoe close to that line.

Many times a computer is so fouled up, a person has to do one of three things: (1) Take it to the shop, (2) Dedicate weeks to trying one thing and then another or (3) take some chances with potent cures.

I think of these potent cures as desperate measures. I present them with no warranty, no promises. In fact, I suggest you only use them when no other option presents itself.

We’ll start with the least desperate of the bunch -- reformating the hard disk and reinstalling Windows. Some experts recommend this process fairly routinely, even for computers that are working. The theory is that you should start fresh once a year or so, removing any conflicts as well as hidden viruses or spyware. I don’t go that far. I only use this tactic when I can’t quite figure out what’s wrong with a computer but am fairly sure the problem is in the software, not the hardware.

If you do it, remember to back up all your data first. Also, make sure you have original disks for the programs you use.

The sequence at that point is: install the operating system; then the programs; then the backed up data.

My next tip is more dangerous. There are times when it will work, you’ll have to decide if you want to take the chance.

Remember floppy disks? Many people still send e-mail to me explaining that some important bit of information is stored on one. But the disk isn’t readable.

One desperate measure is to take the floppy disk apart. Carefully remove the inner circle of plastic coated with magnetic material. Then open a second identical brand new floppy and insert the inner material that you just removed. Put the disk back together. If it works — and it often will — immediately copy the material you need to the hard disk. Keep in mind that if you fail you’re ruined any chance of recovering the data.

Now lets turn to hard disks. When one goes bad, it can take much of your precious data with it — especially if you have not backed it up.

You can easily locate a disk recovery company by typing “disk recovery” into Google. I can’t recommend a specific service since I’ve never used one. But there’s a desperate measure that can help.

If the disk damage is not mechanical — and is software instead — there are programs that sometimes can recover your data. This is relatively safe and does not destroy the data if you fail. I’ll mention a couple of places to find these programs: http://www.runtime.org/data-recovery-software.htm and http://www.recoverdatasoftware.com/. I’m not recommending these programs, just offering examples. You can do a Web search using the terms: data recovery software.

In the worst case, the problem is mechanical. Software usually won’t help here. You’ll often recognize a mechanical problem by clicking or chattering sounds.

This is the point where only a commercial data recovery firm can help. There are some tricks floating around the Web that offer do-it-yourself remedies. I do not recommend them since, if they fail (and they usually do) you lose everything. I’ll tell you about a couple in case you decide to throw care to the wind with an otherwise useless hard disk.

The first one involves freezing the disk. Remove it, put it in a freezer bag and seal. Put that bag in a second bag, squeeze to remove the air, then put the whole shebang in the freezer for several hours.

When you take it out, let the the hard disk return to room temperature. Then reinstall it. If it works, immediately copy the information. Here’s why it might work: contraction from the cold, followed by expansion during the warm-up, can free balky parts.

Another trick that has worked for me is to remove the bad hard disk and tap it two or three times on a hard surface. I do not mean banging it like you’re driving a nail. Tap it.

I was serious in suggesting that you not try the last two tips unless the data on your disk is totally unimportant and you just feel like trying a parlor trick. Why mention them at all? I wanted you to know about them in case you stumble across a glowing review on the Web suggesting them.

Enough desperation for one day. I truly hope you never need to try any of these tips.

I could tell the time of year even if I lived in a windowless cell. E-mail from my readers is the world’s best calendar.

This is when many of you begin to think of buying a laptop for a son or daughter heading to college. I’m several years removed from that necessity, but readers keep me up-to-date. In more than one case, I’ve changed my recommendations based on what you’ve told me.

As is usually true with smart technology purchases, the most important work is done long before the credit card slip is signed.

The starting point is the college Web site. You leave yourself open to costly mistakes if this stop is skipped. Many colleges have specific requirements for student computers. Ignoring these requirements could mean you’d end up buying two computers — the one you select and the type specified by the college.

Also, some manufacturers offer significant discounts for students at certain colleges (but comparison shop to make sure it is indeed a bargain).

In Atlanta, Georgia Tech has definite ideas about computers. Here’s a Web page that lists the requirements: http://tinyurl.com/56lra3.

You’ll see on the same Web page that Tech has purchasing agreements with Apple, Dell and Lenovo. Another link shows you programs that need to be installed on the computer.
Since Georgia Tech is known for engineering and technology, it’s not surprising its requirements are fairly specific. Other colleges may show more general requirements, or none at all. In that case, a call to the school may be prudent.

If you still have no guidance? Well, the specifications on the Georgia Tech site are an excellent start. Even if you end up paying a bit more to get the power called for, you probably will save money over time. That’s because your goal should be to buy a laptop computer that will survive four years of college without replacement.

To boost the odds of computer survival, here are four things to keep in mind.

One: All computers are compromises. For instance, extremely light computers often cost more and may not be rugged enough. Powerful laptop computers can be too bulky to comfortably carry around. The compromise I favor for college use is durability.
One example (though not a recommendation) is the Panasonic Toughbook, made for the school of hard knocks. You can read about it here: http://tinyurl.com/689xnq

Two: Consider insurance and an extended warranty. That goes against my usual recommendation. But parents have told me of broken screens, dropped computers and theft. Make your own decision, but research this option. Some credit cards offer warranty extensions if used for a purchase, so check on that as well.

Three: A good carrying case can add to survivability. I favor an aluminum hard-shell case. If your student considers that impractical, make sure any soft-side case you buy has plenty of padding.

Four: Keep in mind that laptop computers make a tempting target for thieves. There are dozens of devices ranging from cable lock systems that secure a computer in a dorm room, to tracking devices that make it easier to find a stolen computer. For ideas do a Google on “laptop computer anti-theft” or similar words.

Finally, make the student part of the search process. Your young scholar needs to buy into the notion of protecting the laptop. And it’s a good idea to cater to their biases when you make the purchase.

I’m sitting here at the keyboard smiling. I’ve been through this purchasing process twice. It’s a wonderful feeling to know I’ve finally graduated fr