If you use a KVM to share your monitor, mouse, and keyboard between computers and are having problems with your display reverting back to low resolution every time you switch your KVM then this posting is for you. Here's what you do to keep this from happening. Be sure to export your current registry keys before making any changes so you can easily go back to your original setting if need be.
First, go into your power options. Turn off sleep, hybrid sleep, and hibernate. If you have a screensaver get rid of it. If you don't know how to change any of these options google how to do it in your particular operating system. Each version of Windows is different so I can't list instructions for each of them here.
Next, open regedit. Browse to HKey_Local_Machine\System\CurrentControlSet\Control\GraphicsDrivers\Configuration
Locate the key for your monitor. Normally the first few characters will match your vendor. In my case, I use a Viewsonic display, and my key starts out with VSCE********
Expand this key and both of the 00 subkeys. Under the first 00 subkey, document the values for PrimSurfSize.cx, PrimSurfSize.cy, and Stride. Then go to the nested 00 subkey and document the values for ActiveSize.cx and ActiveSize.cy.
Next, locate the key starting with SIMILATED. Modify the values within this key to match the values you noted in the previous step.
Then locate the key starting with KVM and modify its values the same way.
This should fix your problem. Your monitor's resolution should remain at its native setting.
Note that sometime when switching back after an extended period of time you have to wait 10 seconds or so for the resolution to change when using this method. If it doesn't then log out andthen log back in. There's no need to reboot.
