On a fresh Windows XP Pro SP3 installation I installed NOD32 188.8.131.52 (trial). Then I updated the definitions. The only settings I changed was to enable detection of potentially unwanted/harmful applications in two places. After that I disabled temporarily the protection (for 10 minutes) and later tried to restart Windows. During shutdown it stopped and hung there for hours. This was in a VirtualBox VM, with the VB guest additions installed. I also had bo2k.exe on the desktop.