参考：SQL 2008 Fails to Install on Windows 7 sqlenginedbstartconfigaction_install_configrc_Cpu64 Never Completes
Windows 7 AppCompat changes and SQL Server client and setup hangs:
Apparently it is quite a common issue with Windows 7 and Windows Server 2008 R2 .
To allow SQL Server client drivers to connect, set the SbEnable value to 1 and restart the machine."
I did this, then uninstalled SQL Server 2008 R2 and then reinstalled and everything works fine. I also tested Denali CTP1 (SQL11) and this worked fine too.