KVM switch + Windows 7 creates monitor switching nightmare

Anonymous
2009-10-29T16:44:18+00:00

I have a problem with Windows 7 and my KVM switch (Iogear model# gcs1764) which is makes switching via KVM an absolute nightmare.  The iogear KVM does not use drivers nor are any available on their website.

Here's what happens:

I switch from Win 7 (2 monitors) to XP (1 monitor) via KVM.  When I switch back to Win 7 (2 monitors) sometimes Win 7 will throw my desktop to the 2nd monitor (1st monitor goes blank) and opening up display settings only shows the 2nd monitor as existing.  It's as if the 1st monitor is now unplugged which it isn't.  At this point I have to go into display settings, click Detect, and then it re-detects my 1st monitor and "extends" my desktop back out over 2 monitors.  All windows have now been thrown to my 1st monitor and i have to rearrange all my work back across 2 monitors.  This is why KVM switching in Win 7 makes my work life a living nightmare.  This isn't all of it either...

When everything gets thrown to my first monitor, it takes any windows that were maximized and resizes them to about 1/4 my screen size.  Due to compatibility issues between Win 7 and SQL Server Management Studio, Management Studio has a redraw bug that doesn't "re-size" the query window correctly.  So even though I maximize the app, when I start typing in the query window my text disappears about 1/4 the way across the whole window.  The only way to fix this is to save all my work, close the app, and then re-open the app with all my work.  So basically every time I switch computers there's about a 1/5 chance I have rinse and repeat everything I just typed above.  Fun times.

So are there any future fixes planned for this?  I have tried everything and nothing fixes this problem.  I have all the latest Nvidia drivers (my card: Nvidia GTS 250).

Windows for home | Previous Windows versions | Devices and drivers

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

0 comments

401 answers

Sort by: Oldest
Most helpful Newest Oldest
  1. Anonymous
    2010-11-10T15:06:51+00:00

    Here you go Kevin: KVM: IOGear GCS632U Computer 1: Monitor: Samsung SyncMaster 204b Video Card: nVidea Geforce 210 Computer 2: Compaq Persario CQ62 Laptop Monitor: BT156GW01 (Built in laptop display) Video Card: AMD M880G with ATI Mobility Radeon HD 4250 Setup: Desktop with Dual Monitor Support with Windows XP, display extended to Samsung SyncMaster 204b Laptop with Dual Monitor, using Samsung SyncMaster 204b as Primary monitor. When switching, all windows moved to laptop monitor (which has lower resolution). When switching back, windows are moved back but maximized windows no longer maximized. The laptop is a DMZ machine so I do a lot of development remotely. When the laptop was an XP machine, everything stayed where I put it. Now things get jumbled around, moved, resized and it can create a lot of confusion when using Remote Desktop into 4 different machines. I know the KVM is cheap, but I figured if it helped others I would post my configuration too.

    Was this answer helpful?

    0 comments
  2. Anonymous
    2010-11-11T13:17:17+00:00

    I think i found the solution. You must indicate to the video driver to not detect the EDID information and to force it.

    There is a registry key in nvidia driver named : OverrideEDIDflags.  You have to create it to force the edid information

    First, you have to find your 4 digits EDID information : You may use a little program named Phoenix EDID designer (Google is your friend). select your EDID corresponding to your monitor and click on Binary viewer. The 4 digits are the 8 to 11 digits in this binary list. For example, the LG E2240S, it's 1E 6D A3 57.

    Then you have to go to registry in : HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video and found the guid corresponding to your Nvidia card. Look the information inside keys. You should find yours easily.

    For me it's : HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Video{C3139BD6-51C6-4EE9-93C3-BA425FA829F4}\0000

    add the binary value key under 0000 : OverrideEDIDflags

    and write your 4 digits and 00 00 FF FF 04 00 00 00 7E 01 00

    So it gives : 1E 6D A3 57 00 00 FF FF 04 00 00 00 7E 01 00

    Reboot your pc and it works !!! Well, it works for me...

    Francky

    • 1 PC with Win7 x64
    • 1 PC with XP
    • 1 KVM Trendnet TK-209
    • 1 HD Monitor LG E2240S

    Was this answer helpful?

    0 comments
  3. Anonymous
    2010-11-16T20:27:57+00:00

    I'm trying to get to the bottom of this issue but I'm seeing two destinct symptoms here:

    [...]

    Thanks,

    -Richard P.

    My issue is much simpler than the two you've identified:

    I have a Windows XP SP machine and a KVM switch, both corporately owned and managed, so I can't change the OS  to Win 7 or plug in new hardware.   When the monitor is plugged directly into the VGA port of the video card, Windows detects a PnP monitor and correctly sets the resolution to 1440x900.  When the monitor is plugged into the KVM, the EDID is blocked and Windows detects a Default Monitor, and the resolutions available on the slider range from 800x600 up to 2048x1536, but do not include any widescreen formats like 1440x900 or 1680x1050.

    Johnnyxz nailed what we want back in November 2009:

    Please give us the option to turn the automatic screen resolution change-thing off.

    If the user checks a box to "Lock Resolution", the slider should offer *all* resolutions, the user sets the slider to what he wants and hits "Apply", and the video card goes to that resolution and stays there regardless of what monitor is plugged in.

    That seems like a simple enough request that doesn't require debugging various models of video cards, KVM switches, OS versions and patch levels, etc.

    Was this answer helpful?

    0 comments
  4. Anonymous
    2010-11-17T15:36:35+00:00

    I think I've found a solution!  My KVM/dual monitor setup was working just fine for over a year, and all of a sudden I started having this issue.  The solution that worked for me:

    -Show all ghosted and disconnected devices in devicemanager per http://support.microsoft.com/kb/315539

    -Uninstall all monitors

    -Reboot

    After Windows came up and detected my monitors, my KVM setup worked perfectly.  Yay!

    Was this answer helpful?

    0 comments
  5. Anonymous
    2010-11-17T21:19:07+00:00

    I think I've found a solution!  My KVM/dual monitor setup was working just fine for over a year, and all of a sudden I started having this issue.  The solution that worked for me:

     

    -Show all ghosted and disconnected devices in devicemanager per http://support.microsoft.com/kb/315539

    -Uninstall all monitors

    -Reboot

     

    After Windows came up and detected my monitors, my KVM setup worked perfectly.  Yay!

    OMG YOU ARE MY HERO

    Was this answer helpful?

    0 comments