Q The 40-gigabyte hard disk on my older Dell Windows XP computer has been giving me this error message when I try to start it: "primary hard disk 0 failure -- no boot device available -- no bootable device." But if I let the PC sit for 10 minutes, then restart it, it works as it should. It seems the computer works only after it has "warmed up." Any ideas?

TIMOTHY LATHROP, SHOREVIEW

A When your disk drive works only part of the time, it's a major warning of impending drive failure. Disk drives fail -- particularly on older PCs -- because they're mechanical devices with moving parts that eventually wear out. (The drive contains a spinning disk with a movable arm that reads and writes data.)

You can test your drive to check its health. If you didn't get a hard disk self-test program with your PC, you can download a software update from Dell.com.

In the Dell.com search field, type in "support 298970." From the resulting list, select "How to Run the Hard Drive Disk Self Test (DST) on a Dell Computer." Find the section of the document for portable computers.

You also should back up the data while your hard drive is still working. One option is to buy an external hard drive and copy all your data to it for safekeeping. Another choice is to go to a repair shop and have your data copied to a new hard drive for your existing laptop, or to the hard drive of a new computer, if you decide to buy one.

Q Recently I watched baseball games at friends' homes where new flat-screen TVs were proudly displayed. But the people on these new screens appeared to be about 15 to 20 pounds heavier and a bit shorter than they appear on my old-fashioned picture tube screen. It is as if the picture is "spread out" to fill in the rectangular shape of the new screen. Can this be? If so, why would I want an HDTV?

KENT BRANDT, PLYMOUTH

A The screens you were watching had stretched a non-HDTV image to fit the HDTV's wider screen. The picture didn't fit because a standard TV screen is 4 units wide by 3 units tall (the units can be anything), while an HDTV is a wider 16-by-9 format.

But you can change the HDTV settings so that an old TV show such as "I Love Lucy" is displayed in either widescreen (Lucy looks heavier and shorter or part of the top and bottom of the picture are cut off) or original format (Lucy looks normal, but there are black bars on either side of the picture). This will continue to be an issue because cable and satellite TV are likely to keep offering non-HD formats (some analog, some digital) and people already own VCR and DVD video in the 4-by-3 format.

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