Q: I recently read in your column (tinyurl.com/jh3mvoy) that I should change the way my Windows 8 PC receives updates if I want to avoid upgrading to Windows 10. But if I restrict which updates are installed on my PC, how do I know which ones to accept?

Barb Fancher, Akron, Ohio

A: The settings for Windows Update create the confusion you describe. Changing those settings will make it easy to separate the updates you want from those you don't.

The updates you want are the so-called "important" updates that fix critical security, privacy or reliability issues. Installing these updates is a must.

The updates to avoid are called "recommended" and "optional" updates. These include software updates, new features and "nice to have" items. Why wouldn't you want those things? Because Microsoft hopes to automatically install Windows 10 on most compatible PCs — whether the owners want it or not — by changing it to a "recommended" update instead of an "optional" one.

Here's how the Microsoft plan works. The company's recommended settings for Windows Update blur the distinction between "important" and "recommended" updates by including them in the same list. That way you're likely to install both, and thus inadvertently install Windows 10.

To prevent that, you need to draw a clear line between "important" and "recommended" updates. Set Windows Update so that it will install only important updates (see the Windows 8.1 section at tinyurl.com/hdjato5). That causes "important" updates to be listed separately on your screen, while "recommended" and "optional" updates will be in another list. Once "important" updates have been separated from "recommended" ones, it's easy to shun Windows 10 if you want to.

But if by chance Windows 10 is downloaded to your PC and starts to install, you'll still be given a chance to cancel the installation.

Q: I've been running a used Windows 7 laptop for seven months without problems. But now I need help to delete old computer files that appear to be useless. Can I delete one such file called "Windows.old"? And is there a program I can use to get rid of such files?

Also, some Windows file folders won't open for me because I apparently don't have the necessary administrator's rights, even though the Control Panel says I do. What can I do?

Dean Skoog, Big Lake, Minn.

A: It appears that your used computer has been upgraded to Windows 7 from a previous operating system. The files and data from that earlier version of Windows reside in the folder called Windows.old, which you can now safely delete.

To get rid of Windows.old and other unneeded computer system files that take up hard drive space, use the "Disk Cleanup" feature of Windows. For Windows 7-specific directions, see tinyurl.com/onhacpy.

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