I have a Python 3.5 64 bit program (required by tensorflow for Windows) that uses OpenCV. I am distributing it with pyinstaller.
I built my program with Windows 10
If you would have provided your spec file I'd could see what's going on. From here its likely your not including files.
There is two methods to go from here:
Check add binary (incl. dll) files here the pyinstaller documentation about including files manually.
Check add data files here the pyinstaller documentation about including files manually.
An example spec-file that includes dll files from your dll folder.
block_cipher = None
a = Analysis(['minimal.py'],
pathex = ['/Developer/PItests/minimal'],
binaries = [ ( 'C:\Program Files (x86)\Windows Kits\10\Redist\ucrt\DLLs', '.' ) ],
datas = [ ('helpmod/help_data.txt', 'helpmod' ) ],
hiddenimports = [],
hookspath = None,
runtime_hooks = None,
excludes = None,
cipher = block_cipher)
pyz = PYZ(a.pure, a.zipped_data, cipher = block_cipher)
exe = EXE(pyz,... )
coll = COLLECT(...)