Best Server OS with XP on desktop?

Our worldwide enterprise of about 80k users are on various platforms including NT 4.0. In few months we're migratiing to XP Pro on the workstations and Win2k on the server side.

Testings have been very exhausive and as a cautious finacially institution with complex apps a lot of which are legacy and propriatory, the decision is bllions dollars worth that you may take advantage off.

Howver, choosing the route to go will depend on several factors. Are you simply migrating over existinginfrastructure? Is Active Directory part of your implementation strategy? How tightly are you integrating your messaging technology? etc etc. You really should consult an engineer for an educated choice. 7000 user community is big enough to invest on feasibilities and implementation strategy.

Goodluck!