According to the MS documentation, calls to CreateProcess must quote the module name in order to avoid ambiguity, see https://msdn.microsoft.com/en-us/library/windows/desktop/ms682425(v=vs.85).aspx 

The lpApplicationName parameter can be NULL. In that case, the module name must be the first white space–delimited token in the lpCommandLine string. If you are using a long file name that contains a space, use quoted strings to indicate where the file name ends and the arguments begin; otherwise, the file name is ambiguous.

One ambiguous CreateProcess call can be found in http://svn.apache.org/viewvc/openoffice/trunk/main/setup_native/source/win32/customactions/shellextensions/registerextensions.cxx?revision=1530306&view=markup#l314