I recently bought a KVM switch on eBay. It's a Keyboard, Video and Mouse switch. It allows you to use one keyboard, mouse and monitor to control two computers.
I was anxious to get it and try it out. I have two computers hooked up in my bedroom, My main computer and one I call my test computer. My test computer is, of course for testing out utilities, programs, and even Operating systems.
Anyway, My main work space consists of a large desk that currently has two monitors and a TV on it and I would like to clear some space by just using one monitor. A KVM switch is just what I needed.
After I got it and hooked it up .... nothing but a blank screen. The first thing that crossed my mind that it was a bad time for my video card to conk out, but upon further investigation, it seems the switch changed my video resolution higher than my monitor can handle.
I had dealt with this problem before. I had at first cursed both Microsoft and the video card manufacturers for not providing a way to reset video cards that have not been set up properly.
I started up in safe mode to delete the video drivers, because you cannot change your video drivers settings in safe mode in most cases. Windows only loads a very basic vga driver and all the properties listed are for that driver only. If I deleted the main video driver in the device manager tab and restarted the computer Windows would reinstall the driver again automatically on restart with more compatible settings.
But for some reason I remembered seeing in the menu choices the option to start up the computer in Enable VGA mode. I've never used it before and when I went to the control panel, in safe mode, most of the control panel icons where missing including the system icon that led to the device manager (WinXp). Another problem yet to fix.
So I decided to use the Enable VGA Mode option. But I wanted to set that option here without having to restart in safe mode again. I knew it had to be in the MSCONFIG utility. So I clicked on Start, then Run and then typed in msconfig and hit enter.
Clicked on the BOOT.INI tab, didn't find any VGA option but did find an option called /BASEVIDEO. I assumed it was the one and checked it and then restarted the computer and let it boot up normally.
Sure enough it started up in a basic 640 x 480 mode with 8bit colour. Which allowed me the access I needed to change the video driver settings without having to delete them (you learn something new everyday).
But the story continues ..... I'm one of those people who rarely turns of their computers. A few days later when I did have to restart my computer for some reason, it kept resetting to this basic VGA mode. I couldn't understand it. I checked out online about others having similar problems but I finally solved it when I realized that I still had the /BASEVIDEO option checked in the MSCONFIG utility.
So I unchecked it , restarted the computer a couple of times, just to be sure. Just a note, I don't think the KVM switch is damaged. I believe that my antique rigs just couldn't handle the setup.
update: 3:19 PM August 23, 2010
I just bought this big hunkin monitor at a yard sale for $5. It is a ViewSonic Professional Series P95f+ monitor with a 19" screen. It as an higher resolution setup so I tried my switch a second time and this time it worked. Confirming, in my mind at least, that what I said about my old technology interfering was the cause of the switch not working.
The downside was that the monitor was blinking very hard on my eyes. I had to disable it again, but getting closer. Maybe someday I'll be able to buy a new monitor and make it work the way it's supposed to.