I checked TPkd.sys on my system. It's an Interlok system file Anti-Piracy from PACE. Both Poser5 and Avatarlab use the same registration procedure and both programs have problems. I guess they are related to this file.
The TPkd.sys version in my old WinK2 partition is 4.1.1.1074, in the new one 3.0.7.840. Don't ask me why these versions are different, I used the same CD and patches to install Poser 5 on both partitions.
I now replaced the 4.1.1.1074 version with the 3.0.7.840 in my main WinK2 partition and, oh wonder, Poser5 and AvatarLab are now running. It was not a problem of the registry.
I have put the 3.0.7.840 TPkd.sys version on my website

http://www.saraproft.lu/download/TPkd.sys

to help other users who experienced the same problem (hi Buck). I hope that this support will not violate any copyright.
Marco B. , Luxembourg