This is really frustrating: We have customers to whom we've sold Cisco VPN solutions but also customers to whom we've sold Nortel VPN solutions. Trying to have both vendors' VPN clients installed on my laptop (so that I can conveniently provide support without having to have two hard drives or multiple boot partitions) is an exercise in frustration and Windows registry brinksmanship. It's unbelievable to me that two companies that author VPN clients which purport to support the IPSec standard dance around this problem. In the past, I've even seen Cisco publish answers to the question "Can I have VPN Clients from other vendors, such as the Nortel Contivity VPN Client, installed simultaneously with the Cisco VPN Client?" first as "Yes", then as "No" presumably due to Cisco and/or Nortel software updates. In my opinion, it's in both companies' best interests to coordinate interoperability of their IPSec clients with at least some of their VPN appliances. Until that day ever arrives (very doubtful, I know) has anyone ever come up with a way to conveniently get both clients loaded on the same hard drive boot partition without eventually trashing things? If so, how do you keep things peacefully co-existing through release updates (by either company), since no one in either the Cisco or Nortel VPN client software development groups appears to know (and/or care) what each other is doing.