To give some background, I just moved my IIS6 server to IIS7. Easy as our pages and web structure was very simple. All I did was move my inetpub, republish the site in IIS7, Installed the new FTP role, Installed SharePoint v3 and fixed a small issue with the database not working because my IIS7 runs...

What happen if i download trail version of IIS server and run that setup.exe file ? it will work or i have to upgrade my OS.