filename doesn't chagne

[MrAlex]

this is the code:

#include <stdio.h>
#include <string>
#include <iostream>
using namespace std;

int main ()
{
  int result,i,j;
  char oldname[] ="C:\Users\Alex\Desktop\oldname.txt";

 char newname[] ="newname.txt";
  result= rename( oldname , newname );
  if ( result == 0 )
    puts ( "File successfully renamed" );
  else
    perror( "Error renaming file" );
  cin.get();
  return 0;
}

and it doesn't find it
it says the the word:"Users" is incorrectly formed universal character name