Current code (in Winpython 2016-01 Python 3,5,1,2 _64bit) for pyuic4.bat is :

@echo off
if "%WINPYDIR%"=="" call %~dp0..\..\scripts\env.bat
python "%WINPYDIR%\Lib\site-packages\PyQt4\uic\pyuic.py" %1 %2 %3 %4 %5 %6 %7 %8 %9

it gives me :

'C:\Program' is not recognized as an internal or external command, operable program or batch file.
'python' is not recognized as an internal or external command, operable program or batch file.

I get it to run with these modifications : (notice the quotes...)

@echo off
if "%WINPYDIR%"=="" call "%~dp0..\..\scripts\env.bat"
"%WINPYDIR%\python.exe" "%WINPYDIR%\Lib\site-packages\PyQt4\uic\pyuic.py" %1 %2 %3 %4 %5 %6 %7 %8 %9