this guy from microsoft says it's no problem, while another guy on SO says, 2 years later, that it can't be done.
When I try to run the CRM 4.0 installer on my win 7 pro machine, I get an error saying my OS isn't supported.
Can anyone shed any light on this?
It is still not possible (server parts). The blog post only states that Dynamics CRM 4 is compatible with Windows 7 (or please show the quote to which you are referring to). However, this only refers to the Outlook Client (and the E-Mail Router)