Q: I have a Dell Inspiron 1545 PC that runs Windows 7. I've heard that Microsoft is no longer providing security updates for Windows 7. Should I upgrade the PC to Windows 10 or discard the computer?

Tom Dominise, St. Louis Park

A: Neither. Windows 7, now 7 years old and still used by 47 percent of the world's PCs, will be safe for another three years. While Microsoft is no longer supplying enhancements for Windows 7, it will continue providing security updates until January 2020 — and that's what matters.

Dell says your PC is too old to be upgraded to Windows 10, and as a result it doesn't provide the driver software (used to control PC components) that your model would need. If you want Windows 10, you will need to buy a new PC.

Q: Windows Update no longer seems to work on my Windows 7 laptop; the program runs but never finds the updates. My security software can't find anything wrong. What can I do?

Roger Kormendy, Prior Lake

A: There have been many complaints about the slow pace of Windows 7's automatic update software (caused by a previous update gone awry.) But there is a way to speed things up.

Experts recommend that you manually download and run Microsoft security update KB3153199 (see tinyurl.com/htvmcft if you have 32-bit Windows 7, or tinyurl.com/joehnqx if you have the 64-bit version of the operating system).

The 32-bit and 64 bit designations refer to the way the PC handles and stores information. If you don't know which one your PC has, you can find out by going to Control Panel and clicking System.

While this is a security update for Windows 7, it also makes Windows Update operate faster. Some users say their update time was reduced from hours to minutes.

Q: I've had my PC serviced twice after receiving an error message about a "bad pool header." But the technicians said they couldn't replicate the error, and so couldn't fix the PC, which I had upgraded from Windows 7 to Windows 10. What's wrong?

Jim Cira, Granger, Ind.

A: The "bad pool header" error can be caused by several different types of PC flaws.

One possibility is a software flaw, which could be in the driver software, the registry (a database of PC settings), or in Windows system files.

Another possibility is a conflict between a PC program and the PC's security software. The error could also be caused by a flaw in the PC's hard disk or RAM (random access memory) chips.

Because outdated driver software is a major cause of trouble in Windows 10 upgrades, your first move should be to download Windows 10 drivers from your PC manufacturer's website.

If that doesn't solve the problem, the solution could be as simple as uninstalling some recently added software or as inconvenient as having to reinstall Windows 10. For details on some potential fixes, see tinyurl.com/hr8meor and tinyurl.com/hxb7888.

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