Q: I recently added information to a Microsoft Word file in Microsoft Office 2000, then saved my changes and closed the file. But now the file seems to have disappeared. What's wrong?

Dave Harrell, Metairie, La.

A: Microsoft Word typically doesn't lose files unless there's some obvious cause, such as Word abruptly shutting down or the computer losing power.

One possibility (with Word or any program) is that you've inadvertently stored the file in a different PC folder than you usually do, or that the file was accidentally deleted and sent to the recycle bin. If so, you can find the file with the Windows search function (see tinyurl.com/ztbko6p).

Word also has some special ways to retrieve lost information (see same website), such as looking for Word's backup, auto-recover or temporary files.

If you can't locate the missing file using any of those methods, you may have a hard drive problem. Disappearing files and folders are one indication of impending hard drive failure. Other signs include clicks or grinding sounds, garbled information in files or long wait times for a file to be retrieved (see tinyurl.com/gu8fru7).

If the drive appears to be failing, back up its information to flash drives or an external hard drive. Then find your PC's "product key" and use it download a new copy of Windows 7, 8.1 or 10 to a DVD disk or a flash drive (see tinyurl.com/ommapnj). If you can, use another PC to download the new copy of Windows. After you replace the hard drive, install Windows on the new drive.

Q: The Blu-ray drive in my HP Pavilion dv8 laptop will no longer play high-definition Blu-ray movie discs, but it still plays standard DVDs. Do you have any suggestions?

Tony Williams, Hollywood, Fla.

A: Your Blu-ray drive probably needs to be replaced. The drives have two lasers, one to read Blu-ray Discs and the other to read DVDs and CDs. My guess is that the Blu-ray laser either has a lens problem (and thus can't read the disk) or has failed electronically. The other laser is still functioning, so the drive can still read DVDs.

Because most new PC Blu-ray drives cost $50 to $90, it's more practical to replace your drive than to repair it. (Because your PC was introduced in 2009, any warranties likely have expired.)

In a recent column, I told Al Thompson of Stacy, Minn., that his Windows XP programs were unlikely to work on Windows 10. But David Sadler of Edina pointed out that some old programs will work with Windows 10 if the Windows "compatibility mode" is enabled (see tinyurl.com/o5xyp7x). It even works with Windows 95 programs that are now 20 years old.

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