Fix crash on non-existing keys, higher resolution

Changes:

 - Fix non-existing value from triggering an exception.
 - Allow to copy additional files to the desktop of all WinXP users.
 - Set default resolution to 1440x900.
 - Disable some registry keys which are found to be unnecessary.
Fix BSOD in processr.sys

This results in an "Unknown device" in the Device Manager, but the
machine runs fine otherwise. (This device is a CPU exposed by QEMU
through ACPI).