Novell GroupWise 5.x running on WIN2k

Can anybody assist me in this problem. The corporation I work for uses Novell GroupWise as thier E-mail system. We are currently running version 5.25. Every Time I try to install the GroupWise Client on a WIN2K PRO pc, the install errors out. I believe it is looking for a mail system to be install, although I am not 100% sure. I do know that on Win9X and NT4, you need to have Windows messaginginstalled for GroupWise 5.25 to work. Please help.