ACE unicode version with VC8

change project properties
Project-->ACE Properties...
Configuration Properties-->General:
Character Set : Use Unicode Character Set
C/C++-->Preprocessor:
Preprocessor Definitioins: ACE_USES_WCHAR
C/C++-->Language
Treat wchar_t as Built-in Type: Yes (/Zc:wchar_t)

ACE client application should do the same work to build unicode version.

ace/os.h must be included before windows.h