Luis Lazo

A: There is no way to completely free yourself of "illegal operation" messages, but if you're getting a lot of them, you need to figure out what's causing the problem and what you can do to fix it.If it's always the same program that goes down, it's probably a bug in that program-especially if it always goes down under similar circumstances. Next time it happens, click the error message's Details button. You'll get something like 'EXCEL caused an invalid page fault in module FM20.DLL at 0137:60007585'-not very useful information for most of us.

But if the vendor knows about the bug, those unfriendly numbers will help you figure it out. Visit the vendor's Web site and search for the words "illegal operation" or the numbers from the Details box. With some luck, you'll be able to locate a patch or a workaround.

If you're getting "illegal operation" messages from a number of programs, or if you can't fix the problem through the vendor's Website, a driver may be at fault. Printer and video drivers often cause illegal operations in other programs. In the case of printer drivers, you need not even be printing for the problem to occur.

Updating the driver may do the trick. Or you can try going the opposite route and use a more generic driver. For instance, most laser printers will work with an HP LaserJet Series II or LaserJet III driver. These have been around for a long time, and all the kinks are pretty much ironed out. Video drivers are more iffy. You could use VGA, but you're limited to 640 by 480 resolution. Even SuperVGA may dock you with that limitation. Sometimes there's a driver for a specific chip, like the S3, but in that case, you have to know what chip drives your video card.

By Lincoln Spector