I've given up trying to figure this one out myself. I've installed all the pre-requisites (IIS, SQL Server 2008, .Net, etc) and I can't get Feedback to pass the "Install Feedback Server" phase. The dialog lists my local server correctly (I've set it to "no instance" so it's just the name of the server, no \instance name), and it sees the default website in IIS, but when I hit OK, I get the following message:
Windows NT user or group '\ASPNET' not found. Check the name again.
Changed database context to 'master'.
I have no idea what that means or how to fix it.
Edit: Just so we're clear on some details, SQL Server 2008 is local, it's running, I can access it with SQL Management Studio Express, and the ASPNET user IS present on this machine.