Blender 2.78c crashes on startup This message is displayed in the command prompt when I launch Blender:

    Switching to fully guarded memory allocator.
read file
  Version 272 sub 2 date unknown hash unknown

ordered
 OBCube
 OBLamp
 OBCamera
AL lib: (EE) UpdateDeviceParams: Failed to set 44100hz, got 48000hz instead
ED_screen_refresh: set screen
found bundled python: C:\program files\blender foundation\blender\2.78\python
Fatal Python error: Py_Initialize: unable to load the file system codec
  File "C:\Python26\Lib\encodings\__init__.py", line 123
    raise CodecRegistryError,\
                            ^
SyntaxError: invalid syntax

Current thread 0x00000e0c (most recent call first):
AL lib: (EE) alc_cleanup: 1 device not closed


Any idea why Blender is crashing? Is my python version wrong? :(
Uninstalled my old python version. Blender is running now.