That's absolutely not the case. One of Microsoft's strengths has always been backwards compatibility, and the ability to run legacy applications in compatibilit

That's absolutely not the case. One of Microsoft's strengths has always been backwards compatibility, and the ability to run legacy applications in compatibility mode. I work in a large organization with literally hundreds of legacy medical applications running on XP. We're planning a migration to Windows 7 as all of the apps have been certified with the exception of IE6 dependencies (which will be delivered via Citrix). We could certify approximately 0% of our applications by switching to CentOS.