I've just downloaded and installed and ran speccy for the first time. In the Operating System section under Windows Security Center, it tells me that Antivirus is disabled.
However, If I go to Security Center, it doesn't give me any errors. I'm running Microsoft Security Essentials.
Seems to work okay here (WinXP+SP3 German, avast! 5, Speccy 1.07.205 Portable):
Operating System
MS Windows XP Professional 32-bit SP3
Installation Date: 18 October 2010, 17:20
Serial Number: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX
Windows Security Center
Firewall Enabled
Antivirus
Antivirus Enabled
Company Name AVAST Software
Display Name avast! Antivirus
Product Version 5.0.83886757