As a consequence of the recent outbreak of the 'Sasser' virus, Microsoft are advising Windows 2000 system administrators to install the "Security Bulletin MS04-011" patch on their systems.
Our tests on Windows 2000 show that if you have install this patch you will no longer be able to run analyses with CIRCLY 3.0 or 4.0.
The symptom is that you will get the following Fatal error message when you try to run an analysis:
Abnormal program termination
Stack fault CSEIP = 000Fh00001373h
We can't fix it due to reasons beyond our control (note that the same problem occurs on ALL Windows XP systems).
Your only option is to upgrade to CIRCLY 5.0 - this will run on all current Windows versions.