cannot convert parameter 1 from 'char' to 'LPCWSTR'

I keep getting this error: cannot convert parameter 1 from 'char' to 'LPCWSTR'

int main(int argc, char argv[])    
{

   // open port for I/O
   HANDLE h = CreateFile(argv[1],GENERIC_READ|GENERIC_WRITE,0,NULL,OPEN_EXISTING,0,NULL);

   if(h == INVALID_HANDLE_VALUE) {
       PrintError("E012_Failed to open port");

can someone help?