Q: I was recently told that it will harm my tablet computer if I power it down after every use. Is that true, and, if so, why?

Mike Segelstrom, Oak Park, Minn.

A: No, it's not true. Most people don't power down their tablets because it's unnecessary, not because they're worried about damaging the device. Tablets are designed to run continuously for at least a week at a time if you keep them charged, and they use little battery power when idle.

So why would anyone warn you not to power down a tablet? In theory, the more times you turn a computer on and off, the more quickly you wear out its circuitry or moving parts. But that's less true with tablet computers than with PCs.

Unlike PCs, which have mechanical components such as disk drives that can wear out, tablets don't have many moving parts. And a tablet's flash memory chips (which take the place of a disk drive) are designed to last up to 100,000 uses.

Under what circumstances should a tablet be turned off? When you're installing an operating system upgrade (the shut down and restart is typically automatic) or to clear up erratic behavior (a shut down and restart clears memory that the device uses to run, which solves many problems).

Q: My three PCs with Windows 7 installed keep getting messages about upgrading to Windows 10. But none of the PCs has a touch screen, so is it worth upgrading them?

William Frost, Paso Robles, Calif.

A: While you can use a touch screen with Windows 10, you don't need one. The operating system runs well with a mouse-and-keyboard user interface similar to Windows 7.

Base your upgrade decision on whether you like Windows 7 or have software that requires it, and on whether you want the new features of Windows 10, such as the digital personal assistant Cortana or the Edge Web browser. For a list of new Windows 10 features, see tinyurl.com/pkloej6.

There's one other thing to consider: While Windows 10 works well on new PCs that were designed for it, it hasn't always functioned properly on older PCs that were upgraded, even if the PCs appeared to meet all the Windows 10 requirements.

Several readers who followed my instructions for eliminating the recurring "Get Windows 10" update message on their PCs (see tinyurl.com/jh3mvoy) said the process didn't work for them. So here's an alternate strategy: Download the free and widely recommended GWX Control Panel program (tinyurl.com/qauay2q) that disables the Windows 10 upgrade message for you. Note that you may need to run the program more than once, because Microsoft has become more aggressive in pushing Windows 10 through its Windows Update service for consumers. For details on Microsoft's approach, see tinyurl.com/juhfwhj.

E-mail tech questions to steve.j.alexander@gmail.com. Include name, city and telephone number.