Tom, have followed your procedure, now have just one version of rtcdll.dll on my Pc, now at V5.2.4949.1001
wil have to wait for friend to get on his comp before I can try it out fully. video checks out speakers and mic working but can’t tell if sending audio works. Thanks for you help.

Thanks to TOM HYDE

This is what I did

1. Search Pc for rtcdll.dll should find 3 copies delete all
2. XP will try to replace, ignore error message.
3. re install MSN Messenger 6.1
4. reboot
5. I checked again how many copies of the DLL file existed to be confident and only one did.
6. I also reloaded my camera software, rebooting again

tried it out and all works, yes video conferencing in MSN Messenger

thanks again to TOM HYDE