How to Clear CMOS

Introduction

Add the following code in an MFC application or make Win32 Dynamic link library and then add the code. It works fine on Win9x only, it was not tested on XP/NT and hope it won't work on NT based tech.

The intension of this code is only for educational purposes. This code is for those who are too lazy to open their cabinet and remove the batter. No remote CMOS clearing routine is specified, so no questions should be posted for the same.  

How To Use It

Come on, you know how to... 

int __stdcall Clear_Cmos( )
{
_outp(0x70,0x2E);   //password will get cleared
_outp(0x71,0xFF); 

/* if you want to clear whole CMOS
use following code
for(int i=0;i<256;i++)  // whole cmos will get cleared
{
   _outp(0x70,i);
   _outp(0x71,i); 
}
*/
return 0;
}

History

• 27^th November, 2003: Initial post