System Information
OS Name Microsoft Windows 10 Professionnel
Version 10.0.17134 Build 17134
System Manufacturer Dell Inc.
System Model Precision 5520
System Type x64-based PC
Processor Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz, 2901 Mhz, 4 Core(s), 4 Logical Processor(s)
BIOS Version/Date Dell Inc. 1.9.4, 4/23/2018
Total Physical Memory 15.9 GB
Available Physical Memory 8.63 GB
Total Virtual Memory 18.7 GB
Available Virtual Memory 9.75 GB
Page File Space 2.88 GB
Page File C:\pagefile.sys
Kernel DMA Protection Off
Virtualization-based security Not enabled
Device Encryption Support Elevation Required to View

Graphics card :
Name NVIDIA Quadro M1200
PNP Device ID PCI\VEN_10DE&DEV_13B6&SUBSYS_07BF1028&REV_A2\4&75D7284&0&0008
Adapter Type Quadro M1200, NVIDIA compatible
Adapter Description NVIDIA Quadro M1200
Adapter RAM (1,048,576) bytes

Blender Version
Broken:

Blender 2.79 (sub 0)

build date: Mon 09/11/2017
build time: 07:44 AM
build commit date: 2017-09-11
build commit time: 10:43
build hash: 5bd8ac9
build platform: Windows
build type:
build c flags: /W3 /w34062 /wd4018 /wd4146 /wd4065 /wd4127 /wd4181 /wd4200 /wd4244 /wd4267 /wd4305 /wd4800 /we4013 /we4431 /DWIN32 /D_WINDOWS /W3 /nologo /J /Gd /MP /openmp
build c++ flags: /W3 /w34062 /wd4018 /wd4146 /wd4065 /wd4127 /wd4181 /wd4200 /wd4244 /wd4267 /wd4305 /wd4800 /we4013 /we4431 /DWIN32 /D_WINDOWS /W3 /GR /EHsc /nologo /J /Gd /MP /EHsc /openmp
build link flags: /MACHINE:X64 /SUBSYSTEM:CONSOLE /STACK:2097152 /INCREMENTAL:NO  /NODEFAULTLIB:msvcrt.lib /NODEFAULTLIB:msvcmrt.lib /NODEFAULTLIB:msvcurt.lib /NODEFAULTLIB:msvcrtd.lib  /ignore:4049 /ignore:4217 /ignore:4221
build system: CMake

Short description of error

Blender does not consider the environment variables which I declare in my startup batch script (cf. enclosed _LaunchBlender.bat).

Exact steps for others to reproduce the error

When I use the enclosed batch script to start Blender on Windows, Blender starts but the two environments variables which are declared in the batch file (BLENDER_USER_SCRIPTS and BLENDER_USER_CONFIG) are not set in the running blender session.