No, I was mentioning the 'migration' and new systems, not about they using the present system / OLD PC.
For examples, computer came to schools in Kerala recently only (not in central schools, but the state schools), so going for legal win in every PC will cost them a lot and the syllabus is best suited for LIN too, so the best option is LIN, it saves a lot of $$$
For banks, if they are using win 95 and any old banking s/w for the last 10 or 15 yrs, and decide to continue with that, nothing wrong in that as they are not spending additional $$$. But truth is, they are opening new branches, they are buying additional PCs, they are making / upgrading / buying new softwares for banking, so they will have to think of buying OS as well. Again $$$ matters.
And yes, if the banking software works on Win only, then there is no option than usin Win.
My point is there are a lot of places where Lin can very easily replace Win, saving lot of $$$
I go for this logic
100 XP = 3500 x 100
100 Lin = 50 x 100, may be less as a single CD/ DVD can be used to install in more than one PC.
So why spending a lot when
a. It is not needed
b. Alternative is there with a much much low cost