I thought I had met my enemy and its name was nvlddmkm.sys.
Perhaps you’ve heard of nvlddmkm.sys, but I hope you haven’t. Yes, it’s a file. It’s a driver file used by Windows Vista to control the NVIDIA series of graphics adapters. And I believed it was my personal pain in the ass for the past three days.
About midday Saturday I decided to take a break from writing to play a round of Call of Duty (CoD). I never got to play. As I was joining an online game, my computer screen froze and the sound sputtered. I had to manually restart the PC.
Trying the play the game again met with the same results. That’s when I started to get concerned, but not seriously so.
As I continued to work, I noticed the screen occasionally blanking. Then, eventually, the screen blanked for good. The computer froze. I had to restart. Finally, I got concerned.
A quick review of the Windows System error logs showed that the video driver was having problems. Specifically, the driver was named nvlddmkm.sys, which is used by my PC’s GeForce 8800 GT graphics adapter.
In my PC Troubleshooting books, I write that problems with your computer are often the result of some sort of change. Yet, there hadn’t been any changes to my PC; everything worked well on Friday, no new hardware or software had been installed. Then the video system all went to crap on Saturday. Of course, hardware problems can be sudden and unexplained. NVIDIA cards do have problems with overheating.
I downloaded a utility called RivaTuner. It’s a nifty little program that can not only monitor your graphics adapter, it can help you manually set the fan controls to help keep it cooler. (Plus it does a lot of other cool, low-level things. Check it out here.) Happily, RivaTuner showed that my card was not overheating.
A search of the Internet for the problems with nvlddmkm.sys showed that I’m not alone. The recommendation to fix the problem was to uninstall the NVIDIA drivers completely, then re-install them. I tried that. Several times. It didn’t work.
Well, turns out that NVIDIA drivers are not re-installed unless you manually remove them. I discovered that fact after monitoring the file’s time stamp before and after an “upgrade.” So in Safe Mode, I uninstalled the drivers, manually deleted the nvlddmkm.sys file, then re-installed the drives. Sadly, even that didn’t work.
Then I started getting DirectX errors.
Running dxdiag program told me that, surprisingly, my graphics card had its 3D features disabled. That met with a big “Huh?” look on my face, and the final realization that my problem was hardware, not software.
Early Tuesday, I ventured out into the real world and purchased myself a GeForce 9600 GT graphics card with 1GB of video RAM. A monster card. I pulled out the 8800 and plugged in the 9600. I’ve not had a problem since. Yeah!
My guess is that many of the other folks who are having problems with the nvlddmkm.sys driver might also have hardware issues, not software problems. Especially because the computer problem was so sudden, that’s almost an instant clue as to its hardware nature.
For more tips and such on hardware troubleshooting, be sure to check out my book Troubleshooting & Maintaining Your PC All-In-One Desktop Reference For Dummies. Go here.
