CompareStringW

int CompareStringW(
  LCID lcid,           
  DWORD fdwStyle,      
  LPCWSTR lpString1,   
  int cch1,            
  LPCWSTR lpString2,   
  int cch2             
)
 

Limitations

Only accurate for character values less than 128. Characters whose values are greater may not be compared accurately because the 16-bit implementation does not have the necessary Unicode mapping tables.