can't unpack the .cab files for the Surface Pro 2
Explain please. If you have a .cab file you could use the expand utility to open it.
something terminating the installation of the SurfaceProUEFI.inf file.
ProcMon could give you some clues about that.
The Registry HKEY_LOCAL_HARDWARE DESCRIPTION /SYSTEM /SYSTEMBIOSVERSION .
OEMA - 1072009
2.05.0250
American Megatrends - 4028E
The Panther files will be associated with your last cumulative update.
Setupact.log contains this
2018-07-10 16:02:56, Info SP Host system information:
VM: NO
Firmware type: UEFI
Manufacturer: Microsoft Corporation
Model : Surface Pro 2
BIOS name : 2.05.0250
BIOS version : 2.05.0250
BIOS release date : 20150410000000.000000+000
Total memory : 8589934592
Number of physical CPUs : 1
Number of logical CPUs : 4
Processor manufacturer : GenuineIntel
Processor name : Intel(R) Core(TM) i5-4300U CPU @ 1.90GHz
Processor caption : Intel64 Family 6 Model 69 Stepping 1
Processor architecture : x64
Processor clock : 2501
BTW are you sure that you didn't get an SP4 as a replacement for your original SP2? That would be a simple explanation for your peculiar symptoms. ; )