Thursday, June 17, 2004

Will Windows work continuously for more than 49.7 days?

Will Windows work continuously for more than 49.7 days?
Here is a bit of information, which may surprise you all.
Windows crashes automatically if you don't switch off the machine for 49.7Days.

Microsoft accepts this!!

Do you know why?

In Windows the Virtual Machine Manager (here after referred as
VMM) is responsible for creation, execution, monitoring and termination of virtual machines. This VMM, which is a 32 bit, protected mode operating system entity, provides a number of system services at chip level. One of these services
is "Get_System_Time".

This particular service loads the EAX register with the time in milliseconds
since Windows started on that machine. This service is accurate to 1 ms.
EAX is a 32 bit register in Intel 386 Processor onwards.
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 Timeout of various Services they provide.
So after 49.7days the drivers cannot use the get_System_Time function of VMM
and they crash taking the OS along.

1 comment:

Anonymous said...

There is tool named as Digeus Registry Cleaner I recommend to use it when there are problems with system. I also use Windsty Tune Up Suite. It improves your Windows PC's overall performance and stability.

Network.Programming-in.Net

Network Programming in .NET