Q: My Windows 7 PC, now five years old, has recently begun to wipe out my personal settings every time it starts up. The programs I've added to the Start menu over the years are deleted from it, and my personalized screen background also disappears. What can I do?

David Lee, Columbus, Ohio

A: The problem is probably caused by missing or damaged Windows 7 files, but you can fix things with some repair software built in to the operating system.

If the "Windows Startup Repair" software is on your PC's hard disk already, you can start up the PC while continually pressing the F8 key. You will see the "advanced boot options" screen; choose "repair your computer." In the next menu, choose "startup repair."

If the repair tool isn't installed on your hard disk, you will be prompted to insert your Windows installation disk (a CD). If you don't have an installation disk, you can create a "system repair disk" on a blank CD (see tinyurl.com/y7nvdbpp).

To begin repairs, put either of these CDs in the CD/DVD drive, restart the PC and press any key to make the PC load from the CD rather than the hard drive. Go through the routine of selecting the language, time of day and other options you want, then click "next." On the next menu, select "repair your computer." Wait while Windows 7 is located on your PC, then click "next." On the next menu, choose "startup repair."

During repairs, the PC may restart on its own several times. Let it load normally from the hard disk rather than pressing a key to start from the CD. When repairs are finished, you will be told to restart your PC again. (For details, see tinyurl.com/jofj4tp).

Q: I've had a problem receiving my AT&T e-mail on three successive Samsung phones, including my current Galaxy S7. Many of the e-mails are displayed in a vertical line of single letters, making them almost impossible to read. These same e-mails are displayed correctly when I view them on my PC. What's wrong with the phones?

Johnny Gomilla, Hammond, La.

A: It may be an issue with AT&T's mobile e-mail server rather than a Samsung problem.

AT&T says one cure for mobile e-mail problems is to access its service via the Yahoo Mail app (Yahoo is the actual provider of AT&T's e-mail service.) The app is available in the Google Play store (see tinyurl.com/6rhmwu4).

Alternatively, you can use AT&T's "Troubleshoot & resolve" service, in which you specify your phone's make and model, then log in to your account (see tinyurl.com/yc5wcueu).

Q: I get long delays when I access Facebook on my 2014 MacBook Air. This doesn't happen on other websites. What should I do?

Andrew Workum, Columbus, Ohio

A: Try using the latest version of a different browser. Among the highest-rated Mac browsers are Apple Safari (tinyurl.com/j8sdddn), Google Chrome (tinyurl.com/ydx6vqvk), Opera (tinyurl.com/ng6t82s), Vivaldi (tinyurl.com/hgsugsc) and Firefox (tinyurl.com/pbcctob).

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