KVM switch + Windows 7 creates monitor switching nightmare

After going through this entire thread and trying several of the no-thanks-to-Micro$oft solutions, I ended up rolling back my display adapter drivers... and it worked.

I'm using an Nvidia Geforce GT 220, dual monitors on a cheapy Raritan 4 port KVM and was having the same issue as many others.  Win 7 on one machine, XP on the other.  Extended desktop hangs tight when switching TO the XP machine, but when switching back, my DVI display would 'go dead' and my VGA display would inherit the desktop from it.

Guess I'll hang out on my old driver version (8.16.11.9062) for awhile.

p.s.

I agree with an earlier poster about the lack of a cursor.  What a nuisance.

This answer sums up my frustration with computers.  Does nobody get it ?  I am a very experienced and capable computer user. Suddenly, my monitors are reversed for no reason...just out of the blue.  I search for an answer.  I get this ...

"

It is a problem found with those KVM switches which did not pass the console display's EDID and DDC information to all the systems connected to the KVM switch.

To solve this issue, just replace the KVM switch with those KVM switches supporting FULL TIME/ Active DDC function.

Please check ConnectPRO new UR or PR serial KVM switches which support Active DDC function to all the ports.

"

Forgive me for having a life but I have no idea what any of this means and I don't want to spend a few months figuring it out.  I just want my monitors to work.  They did yesterday and today they don't.  WTF ?

I also have the single monitor issue. I just setup an Aopen DEX4501 with Intel GM45+ICH9M chipset with GMA X4500MHD, W7 ultimate 64bit, Grundig TV via HDMI. Lates drivers from intel 8.15.10.2202 25Aug2010. Running at 1600x900 as 1920x1080 cuts the edges off the image for some reason. When I turn off the monitor, or switch to VGA (2nd computer) and back the windows are moved resized. The bottom right of the window is now at 1024x768. Microsoft please fix as this os not a good out-of-box experience...

I have found a work-around.

Using Sysinternals ProcessMonitor I found that Windows was accessing the following Registry path;

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration

My system had three entries;

DELF003YY7707BR0MUL_30_07D7_6A^9A3774EB79DEE3E3E38496CC7DF4D936

QHD32000001_31_07D6_D5^63E1ABDD175E7871DCAEB710418A0F75

SIMULATED_8086_2A42_00000000_00020000_1010100^CDE365D1B3F0942F0CF38BFB8E127AB4

Under each is a tree called "00" two of the keys are

PrimSurfSize.cx

PrimSurfSize.cy

Under "00" was another branch also called "00" two of the keys are;

ActiveSize.cx

ActiveSize.cy

The first two of the configs (ie DELF00... & QHD3...) the above keys were 1440x900,

so they were not involved.

The third (SIMULATED...) were set to 1024x768.

I changed these to 1600x900 and the problem was solved.

Further I changed resolution (via control panel) to 1920x1080, the moving/resize issue returned,

but the lower right corner was set to 1600x900, ie the SIMULATED... settings.

So for some reason one of the configs does not get set correctly.

I don't know why there are three configs, I have only ever used one monitor.

Worked for my non KVM switch issue, may help your issues.

I've researched this quite a bit.  I first saw it with Windows 7 but I've since seen it on other operating systems including Linux and Windows XP.  It's not so much an operating system issue as a driver issue.  I have an 8-port KVM which is where my problems started.  I was fine until 6-8 months ago when I started upgrading hardware and software.  The bottom line is that it was really the video card upgrades that were at fault for me, with some blame placed on the operating systems and drivers for their inconsistency in being able to compensate.

One solution, which I'm using for one machine, is to use a DDC/EDID emulator like one of these:  http://www.connectpro.com/prod\_vid\_ddc.html

That's much cheaper than getting a new KVM but, unfortunately, you need one for every connection where the issue exists (not just one for the KVM).

On Linux, with an NVIDIA card, their drivers handle it.  If I run with the stock Linux drivers I can't use high resolutions without screen flashing, etc.  With NVIDIA's drivers, it's handled. I believe that may be a function of X Windows though -- there are ways to configure DDC/EDID settings for the display that compensate for the KVM not doing it.

With NVIDIA on XP, no such luck.  I use NVIDIA's drivers but I have to use the DDC/EDID emulator to get high resolutions like 1920x1200 without the flicker problems.

On Windows 7, with a Radeon card, same thing: without adding the DDC/EDID emulator I have to run at lower resolutions to avoid issues.

In all cases I'm okay with any of the 1600/1680 resolutions and below.

As for replacing your KVM, you need to buy a DVI KVM to get around this without attaching an emulator device.  I did some experiments and my goal now is to eventually move to a full DVI KVM.  I believe only VGA KVM's suffer from this issue (since they were created before the protocol really).  When I use DVI versus VGA I get a much better display.  So ultimately I want to replace my VGA KVM with a DVI KVM that supports DDC/EDID.  That will fix the problem for any machine I plug in and get me better quality displays.  If you read the manufacturer specs you'll see that most or all DVI KVM's discuss supporting this.  There are two issues I've found with DVI KVM's: price and capacity.  Price is a big barrier to me replacing my VGA KVM now but at some point I'll justify spending the money.  Capacity is a bigger issue.  I have an 8-port VGA KVM.  I'm not using all 8 ports but plan on getting there in a year or so (this is a small business KVM).  One reason I got the KVM I have is because I can cascade others to it to go beyond 8 ports if I ever get that far.  There aren't many DVI KVM's with more than 4 ports -- some but not a lot.  On top of that, only a few I found are cascadable.  If you only need 4 ports, then you can get a reasonably priced Belkin or IOGear DVI KVM.  To go higher or get cascadability, you need to start looking at Avocent, Gefen, Adder, or SmartAVI (there are probably more).  Some of those are very nice products but they're all also rather pricey right now.  You will easily spend close to $1000 or more for an 8 port DVI KVM.

It would seem if drivers like NVIDA can compensate on Linux there would be some way to do the same on other systems and with other graphics cards.  That's really what I want now: a workaround to let me use 1920x1200 without buying anything to hold me over until I'm ready to upgrade my KVM.   I find the "upgrade your hardware" answer annoying given the cost difference.  It's not a trivial upgrade for most people who don't have an extra $1000 or so laying around to spend.