Q: I am sick and tired of you recommending Zip drives. Do you have stock in the company?

A: No, I don't--but let me give you some other suggestions.

Come Christmas morning, many folks will find new computers under the tree. The inevitable question involves how to transfer the existing data from the old computer to the new one.

My standard suggestion is to get a parallel-port Zip drive and plug it in the old and then walk over and plug it into the new machine. One alternative is to store your data on the Internet and download the old data to your new machine. There are data-storage locations available--some are free, some are fee-based. Two free ones include Freeback (www.freeback.com) and X:drive (www.xdrive.com).

If you want to move all your existing applications and settings, you might want to take a look at some new products on the market. Desktop DNA (www.desktopdna.com, $245) allows you to transfer programs and data. Eisenworld has a product called AlohaBob's PC Relocator (www.alohabob.com, $69.95). You connect the two machines with a parallel cable, then sit back--it transfers everything.

One caveat: Remember that your drivers (video, modem, etc.) on your new machine probably will differ from those on your old machine.

Q: Is it true that a PC's hard drive will fail after it is turned on 4,000 times?

A: The issue here is this: Should you keep your computer turned on indefinitely to preserve the life of the hard drive?

In the world of hard drives, one way to measure durability is with the abbreviation MTBF--mean time between failure. This is normally rated in terms of hours. A manufacturer such as Seagate Technology Inc. will line up about 1,000 hard drives and test the failure rate. As an example, Seagate's hard drives today have an MTBF of 500,000 hours.

The MTBF rating has nothing to do with turning the darn thing on and off. Vendors also have tests for that aspect of durability. Seagate will not release a hard drive unless it is tested to withstand 50,000 power ups and downs--that's a far cry from 4,000.

If you have a file server, you probably want it running all the time. If you use a machine to receive faxes, you might want to keep it on 24 hours a day. But if you think you are going to maximize the life of your hard drive by keeping your personal computer turned on, you're probably mistaken.

Q: My mouse seems to be sticking, and it is driving me crazy.

A: Even the most fastidious computer users can get dirt inside their mouse. After all, the mouse pad is sitting on your desk all day long absorbing dust and the occasional anchovy. Inevitably, you get some kind of dirt on your mouse pad and it gets transferred to the mouse.

The traditional way to clean a mouse is to open up the bottom, take a cotton swab and alcohol, and carefully clean the ball and the mechanism inside. This will do it for most users.

Some of my readers have tried that approach with no luck. If that is your situation, one of the Microsoft Web site's Knowledge Base articles has a creative solution. Get out the adhesive tape. Fold it so the adhesive part is exposed. Use it on the same areas the alcohol was on. That will take off what is technically called "crud."

After this procedure, use the mouse for at least an hour--you should notice the difference.

Microsoft has a new mouse out that might solve your headaches altogether. It is called the IntelliMouse and does not have any mechanism to clean--it uses light. This mouse isn't cheap ($39.95), but it really gives terrific control. One of the nice things about the mouse is that you can use the USB or the PS/2 port.

John Gilroy of Item Inc. is heard on WAMU-FM radio's "The Computer Guys" at 1 p.m. on the first Tuesday of the month. Send your questions to him at The Washington Post, 1150 15th St. NW, Washington, D.C. 20071, or via e-mail at jgilroy@iteminc.com.