If you search for enabling FTP on Windows Server 2008, you most often get redirected to the following site:
And if you download that FTP7.5 installer referenced on that page and try and run it, you get the following error:
(this version of the operating system is not supported. FTP Service for IIS 7.0 can be installed only on Windows Server 2008).
Turns out that, for Windows Server 2008 R2, you don’t need to download a separate installer. You just need to enable the FTP role. (This is because on Windows Server 2008 R2, you get IIS 7.5 and not IIS 7.0).