Chinese pirates are making a pretty penny installing hacked Win7
The service takes about 40 minutes and includes a full install as well as a quick crack. Win7 Family Edition costs $11.
I haven’t actually seen any Win7 cracks – it just never came up in my searches – but this points to the possibility that either Win7 is hard to install (which I don’t believe is the case) or that the cracks are quite complex right now, similar to the old tricks you had to play with XP.