HELP FILE

Q The USB flash drive I plugged into my computer isn't showing up on the screen. What's the problem with this thing?

AMost of these tiny devices, which store data in solid-state flash memory, work every time: You plug one into a USB port, then it turns on and appears on the computer's desktop. Some, however, draw more electricity than others, an appetite that makes them incompatible with many external USB hubs.

For example, when I plugged an Imation "Swivel Drive" into one of the USB ports on an iMac's keyboard, the Mac popped up an error message instead of displaying the drive's contents. That alert informed me of the power situation and advised me to connect the drive to a USB port on the computer itself, which solved the issue.

This is a manageable problem but an unnecessary one. Unfortunately, there's no easy way to ensure that a USB key in a store won't suffer from this limit; you may only discover this when you take it home. If that happens, your best recourse is to take it back to the store and exchange it for another vendor's model.

The attached e-mail was bounced back to me by Cox when I originally tried to send it. But they ignore me when I ask how to rectify the problem. What went wrong?

The bounce message did include an explanation, but it's not one that most users can readily understand or act upon ("SMTP authentication is required"). In this case, it referred to a brief but maddening glitch with my e-mail address that prevented mail from reaching me.

In a case like this, however, you don't need to decipher the error message to grasp the larger picture: If you only have trouble sending e-mail to one address, the issue is almost certainly not on your end. If it goes away on its own (the reader had no problem sending me the question above), you should feel comfortable declaring victory.

-- Rob Pegoraro

Rob Pegoraro attempts to untangle computing conundrums and errant electronics each week. Send questions to The Washington Post, 1150 15th St. NW, Washington, D.C. 20071 orrob@twp.com.