Q Most articles I've read about computer maintenance recommend periodic hard drive defragging. But I heard that defragging wears out the hard drive. Is this true? And if some defragging is good, is too much defragging bad?

A Since I've written a good many articles recommending regular defragging, this question had me a bit concerned. So I consulted every source I have and ended up with these answers. Yes, you definitely should defrag your hard drive regularly. And though you might damage your hard drive with too much defragging, you'd have to do an awful lot to reach that point.

As you use a hard drive, the files on it become fragmented ù with pieces scattered all over the drive. Fragmented files slow down the drive and increase the likelihood that data will be lost or corrupted. A defragging program reassembles the pieces, making each file a contiguous whole. Windows comes with such a program, Disk Defragmenter; Norton Utilities (www.symantec.com) and Nuts & Bolts (www.helixsoftware.com) offer better ones.

However, the act of defragging gives the drive's moving parts a considerable workout, and moving parts do wear out. If a drive is on its last legs, a defrag operation might push it over the edge. But in such a case, the crash probably would have happened soon anyway.

In most cases, regular defragging actually reduces the wear and tear a drive suffers during normal use. After all, it's easier for the drive head to retrieve a file from one location than from eight. Consequently, a drive that's defragged every two to four weeks should last longer than one that's never defragged.