Windows Server 2003 VHD - Evaluation expired on fresh installation

Hi,
I have downloaded VHD from the below link:
http://www.microsoft.com/downloads/d...DisplayLang=en
The readme.txt file, that it contains, says that this setup will expire on
August 16,2009. But when I tried to install it, it did not give any error and
I was able to install this successfully. The trail period for this setup is
30 days.
But its expiration period kept on decreasing with the time. As a result of
which it got expired in 3 days only. System date of the node is in sync with
the system date of the host. I am wondering how did this happen.
Is there any step to be followed during installation or any workaround to
get rid of this problem?

Quick response is appreciated.

Thanks,
Shivani.