Here I suppose it all depends on what Specialised Software and peripherals are in use and the cost involved in rewriting/replacing them is.
Currently I still support Specialist Software that will run on nothing newer than NT4 and at the moment is given away with multi thousand $ bits of Plant to be used on Construction Sites. The Hardware is useless without the software and the work can not be done economically without the Hardware.
Or the Medical Profession who uses their 1 of 2 Programs which as of yet are not Certified to run on 7 or latter Desktop OS's and has only recently been certified to be used on a 2008 Server.
Specialised Software used in some places simply is not rewritten as fast as most companies would like and a lot slower than I personally prefer.
Of course bigger places can use more of the available options or probably are forced to use different things to just Microsoft depending on what it is that they do. However most small business is stuck with Microsoft as they are the people rightly or wrongly who own the Desktop and small network environment.
Col
