Walt Mossberg of the Wall Street Journal wrote a head-scratching post today. “Windows 8: Not for Old-at-Heart PCs.”

Here’s how it starts:

If you’re thinking of upgrading your PC to the new Windows 8, be prepared for hassles and disappointment, especially if the computer is more than a year or two old — even if it technically meets the basic requirements to run the new version. 

I know this, because I’ve spent big chunks of the past week trying to upgrade to Windows 8 two big-name, well-regarded PCs — a 2008 Lenovo laptop and a 2009 Hewlett-Packard touchscreen desktop. The process was painful, and it resulted in lost capabilities, even though both PCs ran Windows 7 quite well and met the minimum requirements for running Windows 8.

But as we journalists say, Walt buried the lede. Here’s where he should have started:

Part of this problem was my fault, I guess. If I had thought to burrow through the Lenovo or HP websites, I might have found that my models weren’t considered by their own makers to be fit for upgrading.

For instance, HP’s information page, at http://bit.ly/SdTCVp, said this about my TouchSmart, after I located and entered its obscure, official product number: “HP has not tested this PC. For this reason, HP is unable to provide upgrade instructions or Windows 8 drivers. You may lose basic functionality & stability if you try to upgrade.” Alas, I learned this only after I had upgraded.

And even though the post leads with an illustration of the Windows 8 Upgrade Assistant, Walt admits he didn’t run that useful tool:

Microsoft does offer Upgrade Assistant software that might have warned me of the problems, available at http://bit.ly/SdUxFo. But the box for the Windows 8 Pro DVD I was using only suggested running this utility and checking with the manufacturer’s website, in tiny type at the bottom of its back cover.

We’ll never know if the Upgrade Assistant would have spared the hassles that Walt writes about with what seems to be almost glee. But I can tell you how to decrease the likelihood that you’ll have headaches:

1. Backup first. If you’re moving from Windows 7 to Windows 8, you can use an external USB hard drive to create an image backup of your current PC configuration. That way, if anything goes wrong, you can restore your current working configuration without losing a thing. The word backup does not appear anywhere in Walt’s writeup.
2. Do your homework, starting by checking for support at your PC maker’s website. Pro tip: If you think the model number for your PC is an obscure detail, maybe you shouldn’t be upgrading your operating system. If Walt had done this, he would have found this page that specifically says “HP Linkup, HP Application Assistant, HP TouchSmart Magic Canvas and all other HP TouchSmart applications are not compatible with Windows 8 and must be uninstalled before upgrading.” [emphasis added] Then he wouldn’t have had to write that he “lost dozens of programs, such as HP’s touch software suite…”
3. Be especially diligent with notebooks, which are tricky because they often contain custom buttons or require specialized drivers for chipsets, trackpads, and embedded components such as graphics and storage controllers. As Walt discovered, the trackpads on older notebooks are less likely to support Windows 8 multitouch gestures, although they should work the same as they do with Windows 7.
4. If you are one of the few people who bought a Windows 7 touchscreen PC, don’t expect that it will work on Windows 8. The Building Windows 8 team actually devoted an entire blog post to this topic. It includes a list of Windows 7-era touchscreen PCs they tested (the HP TouchSmart Walt tried to upgrade wasn’t on the list).
5. Before you begin upgrading, run the Upgrade Assistant. It will warn you about incompatible software and drivers and even help you uninstall things that will cause problems. It also gives you a very handy checklist of stuff you need to do after the upgrade is complete.
6. See item 1.

And if you start to run into problems, consider it a message from the upgrade gods:

Also, I had problems with the installer itself. On the HP, it wouldn’t work with either the DVDs or a downloaded version of Windows 8. So I had to transfer the downloaded version to a 4 gigabyte USB flash drive to get it to work. (It requires at least a 3 gigabyte drive.)

Frankly, running Windows 8 on a four- or five-year-old PC seems like an exercise in problem-creating to me. The machines were originally designed for Windows Vista. Walt says both PCs were running Windows 7 quite well. So what is the point in upgrading to a new operating system designed for modern touch hardware?