Steve Alexander: Old warning returns and PC goes blank

QRight after I bought a Toshiba laptop in August 2010, I got this error message: "Display driver Nvidia Windows Kernel Mode Driver, version 266.58 stopped responding and has successfully recovered."

The message stopped appearing, but recently the screen goes blank for a few seconds, then the same message reappears. What causes this, and how can I make it stop?

ALICIA VIDAL, CORAL GABLES, FLA.

AThe screen is going blank because there's a problem with the Nvidia graphics chip in your PC.

You may be able to correct the problem by downloading an updated software driver for the chip at tinyurl.com/4vlulk.

If new driver software doesn't solve the problem, there's probably a flaw in either your PC's graphics chip or its Random Access Memory (RAM) chips. If that's the case, you might have a warranty claim.

Clearly it would have been better to deal with the warning message when the PC was new, because your chances of making a warranty claim were better then. But check your warranty's duration; some of Toshiba's warranties are for two years, which would fit your situation.

NOTE: After I told a reader last week that Microsoft's Word and Excel programs don't run on the iPad, several other readers pointed out that there are non-Microsoft iPad apps that allow you to work on Word and Excel files.

The apps, available through iTunes, include "Documents to Go" ($10, Word and Excel), "Pages" ($10, Word) and "Numbers" ($10, Excel). For Microsoft PowerPoint files, try "Keynote" ($10). Thanks to Harlan Blumenthal of Wayzata, Andy Marlow of Hopkins, Mary Ann McCauley of Chanhassen and Diane Willer of Eau Claire, Wis.

QI have twice downloaded the Mac program you recommended for removing supercookies that can track people online. But when I try to open the program, I get a message that Apple's Safari browser can't do it. What's wrong?

JAMES NASTOFF, Minneapolis

AThe Better Privacy program for removing supercookies doesn't work with Apple's Safari browser. You need to download the Firefox browser; for instructions, go to tinyurl.com/3m3mkn2. Then use Firefox to go to tinyurl.com/3swjtez and download the Better Privacy program. After downloading, open the software with Firefox (go the Tools heading, click Downloads, then click on the Better Privacy program.)