Ever since you decide to move from playing VMWARE to VirtualBox you will see when to migrate your XP vmdk disk to VirtualBox your XP will not able to boot smoothly.

When you want to see what happen in "Safe Mode" you will see that it is stuck on agp440.sys hang. So be it, lets we break them down here.

agp440.sys

VMware have an AGP graphics bus which will cause agp440.sys to be installed. VirtualBox' virtual graphics card is on the PCI bus so the driver will cause a system crash.

  1. Insert your Windows XP CD-ROM into the computer CD-ROM drive or DVD-ROM drive, and then restart your computer from the CD-ROM.
      Note Some computers may require that you modify the basic input/output system (BIOS) settings before you can start the computer from a CD-ROM. For information about how to modify the BIOS, see your computer documentation.
   2. At the Welcome to Setup screen, press R to start the Recovery Console.
   3. Press the number key that corresponds to the installation that you want to repair, and then press ENTER.
   4. Type the password for the administrator account of that installation, and then press ENTER. You receive a drive:WINDOWS> prompt, where drive is the drive on which Windows XP is installed.
   5. Type listsvc, and then press ENTER.
   6. Make sure that the Agp440 service is listed, and that the startup type is set to "Boot".
   7. Press ESC.
   8. Type disable agp440, and then press ENTER.
   9. You receive a message that the registry setting for this service was found, and that its current startup state is "service_disabled".
  10. Type exit, and then press ENTER.
  11. If you are prompted to start in Safe mode or Normal mode, start in Normal mode.
  12. Log on to your computer.

Capt from: http://support.microsoft.com/kb/324764

mup.sys

Ok, you've done with agp440.sys hang, next hang will go to this hang on file mup.sys. This is because of the setting of the APIC and IO APIC setting combination, try to wandering trough them you will find the way (i'm saying that change the value on them, enable and/or disable them).

Another cause is the IDE Controller, try to set it to PIIX4 setting.

Hope its help !

R/D.