I am not sure as to which version will be the most economical to buy Windows 7 for following configurations:
1. 3 PC's
2. 2 PC & 1 Laptop.
And How many licences are available for each of these versions, i.e. Home, professional and Ultimate. What is the Starter version.
Starter edition isn't available to purchase serparately... it only comes preloaded on certain computers. If you have 3 computers, then Home Premium is the most economical, given that you can purchase a 3-user edition.
Zoron is referring to the 3-license Family Pack, which (unfortunately) is sold out in the US. There will not be any more made available. (It was 3 Windows 7 Home Premium Upgrade licenses sold for $150, but it now goes for $280 on Amazon). Still, if you want to upgrade 3 PCs, its cheaper than the $330 you'd have to pay if you bought an individual upgrade license for each PC.