I have completely removed all WPI apllications, cleande files & registry with CCleaner 2.23 and reinstalled SQL Server 2008 Express. Then I runed your query and received the same answer as you. But, when I check my system with Microsoft Update they suggest me to install «Microsoft SQL Server 2008 Service Pack 1 (KB968369)». You can see it on screenshot:

I think it's a little bit strange, if WPI installs latest version of SQL Server, including SP1, so why MS Update still suggests me to installl update KB968369? May be there is an issue in MS Update or I'm doing something wrong? Could you explan me? Thanks.