Q: Some irreplaceable information (photos, genealogy data and tax information) was deleted from my CenturyLink e-mail by a technical problem. The company says that all my information is gone and can't be restored. But I've heard that information isn't really "lost" because it's still on a backup drive. I've even offered to pay CenturyLink to find the information.

Is my data really lost, or doesn't CenturyLink want to recover it for cost reasons?

Janet Ikola, Richfield

A: All data centers regularly back up their servers to another disk drive, and restoring a server from a backup isn't difficult. So I think CenturyLink would recover your data if it could do so at a reasonable cost.

The unanswered question is, why might the company be unable to recover your data, or at least not at a reasonable cost? There are several possible reasons, but here's one example.

The data could have been lost when an e-mail server's disk drive suffered a "head crash." That's when the data read-write device that normally floats above the disk suddenly drops, striking the disk and destroying part of the disk's data. If the damage were not immediately discovered, a backup of that server would probably contain no data.

Here's where cost could become a factor. Even in a head crash, some data survives. But the only way to recover it is to pay thousands of dollars to have it plucked piecemeal from the damaged disk. A data center operator might decide that wasn't worth the cost.

Regardless of what happened, CenturyLink isn't under any legal obligation to recover your lost data.

Q: My PC is still running Windows XP, and I maintain its security through a computer store contract. I use the PC for e-mail, golf programs, Fantasy Football, banking and online shopping.

Should I replace Windows XP, and, if so, what should I upgrade to? I'm interested in an upgrade that would take a minimal amount of work and an operating system that would be easy to use.

Bruce Clause, Metairie, La.

A: There's no easy way to upgrade from Windows XP, which was introduced in 2001 and has been replaced by five newer versions of Windows (Vista, 7, 8, 8.1 and 10.)

For example, you couldn't install one of the currently available Windows versions, such 7 or 10, in a way that leaves your data and programs intact. You'd have to back up your data, then wipe out your hard disk by installing a newer operating system. Then you'd need to reinstall any programs you use and recopy your data to the PC.

In addition, many Windows XP PCs don't meet the memory requirement for the newer operating systems of at least one gigabyte of RAM (random access memory.) Even if yours does, it would probably run more slowly with an upgrade.

The best way to upgrade is to buy a Windows 10 or Windows 7 PC for less than $400.

E-mail tech questions to steve.j.alexander@gmail.com or write to Tech Q&A, 650 3rd Av. S., Suite 1300, ­Minneapolis, MN 55488. Include name, city and telephone number.