**System Information**
Fresh Windows 8.1 64bit install, up to date.
Graphic card: ATI Mobility Radeon HD 4670 (Microsoft Corporation - WDDM v1.1)
I have Python 3.4.1 installed (no other python version but I suspect that might not have an impact).
I also have Visual Studio 2013 Update 2 installed.
**Blender Version**
Broken: 2.70a 64bit, 2.71-RC1 64bit
Worked: 2.70a 32bit, 2.71-RC1 32bit
**Short description of error**
On launch, either by double clicking the install icon or by command line "blender" from the installation directory (or the unarchived output for the RC) I get a console window open with nothing displayed, and an error prompt stating:
LoadLibrary failed with error 87: The parameter is incorrect.
In command line, I tried "blender -d" to get more details, with 2.71-RC1 64Bit I get the following output before triggering the same error prompt:
D:\Downloads\web\blender-2.71-RC1-win64\blender-2.71-RC1-win64>blender -d
Switching to fully guarded memory allocator.
Blender 2.71 (sub 0)
Build: 2014-06-12 22:53:31 Windows:32bit Release
argv[0] = blender
argv[1] = -d
read file
Version 267 sub 1 date 1970-01-01 00:00 hash
ordered
OBCube
OBLamp
OBCamera
Note that the "Windows:32bit Release" part is incorrect, this is the 64bit package from the website and it is indeed a 64bit binary (I checked using "dumpbin /headers") so I suspect there is a minor issue in the RC which is not reporting the right thing.
With 2.70a 64bit installed using the installer I get apparently the same problem:
C:\Program Files\Blender Foundation\Blender>blender -d
Switching to fully guarded memory allocator.
Blender 2.70 (sub 0)
Build: 2014-04-11 06:43:29 Windows:64bit Release
argv[0] = blender
argv[1] = -d
read file
Version 267 sub 1 date 1970-01-01 00:00 hash
ordered
OBCube
OBLamp
OBCamera
Both 32 bit variants of these blender versions does launch with no error.
**Exact steps for others to reproduce the error**
Just launch Blender.
Since I installed Windows 8.1 (new hard drive, so totally) I didn't found any way to launch Blender in 64bit yet.