And? I can't see why that is so earth-shattering.
Removing the Computer type- the hal, is the driver equivalent of getting a new mobo. [this is why XP won't work if hal.dll is missing]
Changing it is going to affect everything- IRQ settings, PnP, drivers etc etc- so it's no surprise the drivers need to reinstall, as the settings all need to change...
Personally I find the best one seems to be Advanced Configuration and Power Interface (ACPI) PC - better than the one XP seems to like which is ACPI Uniprocessor PC.
But then, I am averse to Virtual IRQs...