It's been a good week for reader feedback. Here's what some had to say about last week's column on PC disk drives.

Readers Don Kleven of Bloomington and Steve Kurth of King George, Va., said that last week's column about backing up a PC hard drive wasn't as complete as it needed to be.

I was asked whether programs and data could be backed up to an external hard drive, then restored if the PC hard disk failed and had to be replaced. I said no, only data could be backed up and restored to a new PC disk drive; programs had to be reinstalled with a disk or a download.

Casual PC backups do work that way. But Kleven and Kurth noted that an alternative method, using "system image" software, can back up both data and programs, including ­Windows.

"System image" backups can be made using little-publicized Windows features, such as Windows 7's "Backup and Restore," Windows 8's oddly named "Windows 7 File Recovery" and Windows 8.1's ­"System Image Backup." The limitation of these programs is that you can't choose specific programs or data to back up and restore; the entire disk is copied and restored.

Some for-pay programs, such as Macrium Reflect ($70) and Acronis True Image ($50), work around that limitation by making a full disk backup the first time, then copying only the files that have changed during subsequent backups.

But "system image" software isn't a good solution for everyone, because many of the programs are difficult to use, Kurth said. "It's easy to make mistakes even if you are knowledgeable."

Kevin Bluml, an Eden Prairie computer consultant, said my advice about testing a potentially failing hard drive should have included a note of caution.

When Clark Cordes of Lakeland, Fla., asked why his disk drive was mysteriously gaining additional data, I said one thing he could do was to run Windows Disk Check. That would tell him if there were corrupted storage areas on the hard disk, which is one sign of a failing hard drive and would account for more storage space being used.

But Bluml said it isn't a good idea to run Windows Disk Check if a hard drive exhibits other signs of impending failure, such as reading files incorrectly or making excessive clicking sounds. In that case, Windows Disk Check may cause the drive to "overwrite data that it thinks it has safely copied somewhere new," Bluml said.

Cordes needn't worry about this, because his disk drive wasn't making errors or odd noises. But others should look for these warning signs before running Windows Disk Check.

Q: I accidentally threw away the installation CD for my new HP Envy 4502 printer. Where can I get a copy of it?

Curt Hennes, Prior Lake

A: Go to and select your operating system. You can then download the installation software for free or order it on a disk for about $12, including shipping.

E-mail tech questions to steve.j.alexander@ or write to Tech Q&A, 425 ­Portland Av. S., ­Minneapolis, MN 55488. Include name, city and telephone number.