boot – Booting Windows Embedded Compact 7 in virtual machine fails – Stop error 7B

The user interface of some specialized industrial equipment is implemented as an app running on Windows Embedded Compact 7. The OS has been installed on an obsolete industrial touch panel PC (Aaeon GENE-9455 rev.a1.1 motherboard). Regrettably that motherboard is now deceased; power delivery for one of the chips doesn’t come up right and the boot sequence hangs.

The firm that designed it isn’t around anymore and I don’t have access to the source. As I see it, there are four potential ways to fix the machine – they are all painful and not guaranteed to succeed.

  1. Component-level board repair
  2. Sourcing a new old stock or refurbished board from some forgotten warehouse somewhere
  3. Porting the application to different hardware and software
  4. Running the entire OS on a virtual machine, which is then trivial to host on different hardware and software

I’m trying the virtualization route. I imaged the compact flash card, generated a virtual hard disk from it and threw it in VirtualBox 6.1.16. Trying to start the virtual machine however quickly ends in a BSoD of the guest system, with error code STOP: 0x0000007B (INACCESSIBLE_BOOT_DEVICE).

The same issue is apparently common when migrating more mainstream Microsoft OS’s such as Windows XP and 7 to virtual machines. While they may or may not be applicable to WEC7, I have tried the following suggested solutions. Nothing has changed.

  • Telling windows to load all possibly relevant drivers on boot by editing the registry manually. I loaded the SYSTEM hive of the guest system (WindowsSystem32configSYSTEM) as SYSTEM_guest in the registry editor of the host system, navigated to HKEY_LOCAL_MACHINESYSTEM_guestControlSet001services and changed the “start” value of each key to “0” (meaning: start driver during earliest boot phase) for the following keys: aliide, amdide, atapi, cmdide, intelide, msahci, pciide, viaide
  • Trying different virtual storage controller options such as IDE (PIIX3, PIIX4 and ICH6), SATA (AHCI), SCSI (LSI Logic and BusLogic)
  • Automatic startup repair with windows 7 32 bit install disc ISO.
  • Installing new drivers into the image using aforementioned windows install disc. More specifically, Intel ATAPI and AHCI for windows 7 32 bit.