Windows crashes after 49.7 days

pradeep's Avatar, Join Date: Apr 2005
Team Leader
Windows crashes automatically if you don't switch off the machine for 49.7 days.This is accepted by Microsoft.

Do you know why?

In windows the Virtual Machine Manager(VMM) is responsible for creation, execution, monitoring and termination of virtual machines. This VMM is a 32 bit protected mode operating system, provides a number of system service at chip level of programming.

One of these services is "Get_System_Time". This particular service loads the EAX register with the time in milliseconds since Windows started.This service is accurate to 1ms.

EAX is a 32 bit register. So the maximum number of milliseconds it can hold is:

(2^32) - 1 = 4294967295 milliseconds
= 4294967.295 seconds
= 71582.79 minutes
= 1193 hours
= 49.7 days

So after 49.7 days the EAX resets to zero.Most of the Drivers use this Time Service to keep track of the time out of various services they provide. So after 49.7 days the drives cannot use the Get_System_Time funtion of VMM and they crash.
gamehunter101's Avatar, Join Date: Jun 2006
Go4Expert Member
nice interesting fact
Tango Issac Debian's Avatar, Join Date: May 2006
Go4Expert Member
seriously interesting.............................
Vromoth's Avatar, Join Date: Nov 2006
Go4Expert Member
I'm not sure if this would work, but couldn't you have two Get_System_Times and when one reaches its maximum value, it makes the other tick over like in a clock, when the second gets to 60 it makes the minute tick over.

Last edited by Vromoth; 7Nov2006 at 06:42..
shabbir's Avatar, Join Date: Jul 2004
Go4Expert Founder
Quote:
Originally Posted by Vromoth
I'm not sure if this would work, but couldn't you have two Get_System_Times and when one reaches its maximum value, it makes the other tick over like in a clock, when the second gets to 60 it makes the minute tick over.
But probably thats not implemented as of now.