I have a KVM switch for using 2 computers with one screen. My screen is a wide Proview that works best with 1440x900 resolution. If I restart the computer that is not switched on, it boots up to a different resolution. That happens on both computers. How can I make Windows boot up to 1440x900 anyway? is this a hardware or a software thing?

I assume you are making the resolution change after booting the computer. Are you saving the changes by using the apply button and then the save button. If the graphics card is capable of displaying the desired resolution/ refresh rate/ color depth and you have set it, and it works, then you simply aren't saving it properly. Also use the option when changing to Apply the new settings without restarting and then keeping the settings when prompted.

Firstly make sure your KVM supports that particular resolution. When you boot the machine that is active on the KVM windows will detect your monitor type and select the correct resolution you have setup for this monitor. When you boot the inactive one it can't actually see your display type so will setup as a 'generic' monitor. Try setting the display resolution when windows thinks you have a generic monitor and see if this works. If not it could be that you just have to accept this is a limitation of using a KVM. Wizard ICT. Microsoft Certified Professional