win32: use Python's _winreg again This is a partial backout of f1fa8f481c7c. f1fa8f481c7c switched win32.py to using ctypes with the intention to get rid of the dependency on the pywin32 package. But f1fa8f481c7c replaced the usage of the Python standard module _winreg in lookup_reg as well, which was uneeded (note that lookup_reg was later renamed into lookupreg). Basically, we're switching back to the previous _winreg-based implementation, which uses _winreg.QueryValueEx(). QueryValueEx returns a unicode code string. See also: issue3467