I have one GW 8 HP1 client on Windows XP, this client do not remember any
window position. I.e. opening the address book, change the size and position
for the address book, closing GW8 and starting GW8 again, opening the
address book, the address book do not remember the previous position.

IIRR there is a registry key to change this behavior - but I cant remember
the registry key?

Please let me knew this registry key!