> The PC's were a nightmare (not in terms of the hardware, but because of the sofware) from a management and administration perspective. Primarily because of Windows.

That's a human skills problem, not a software problem. Managing a large fleet of Windows PC's is a solved problem if your sysadmins know Active Directory. There are also third party solutions if Active Directory isn't your bag (we used one at a previous company to manage a large fleet of Windows PC's and servers - its name escapes me at the moment).