我如何知道哪个版本的SQL服务器在磁盘上?

I have several Sql Server 2008R2 setup discs around, but they're not labeled with which edition (standard, developer, enterprise etc.) they are for. Running them doesn't give much help as it just shows that it's a Sql Server 2008R2 install - nothing more specific (unless I'm looking in the wrong place). I'm hoping that one of you smart cookies will be able to point me in the right direction to find out the edition of Sql Server on the disc.I have several Sql Server 2008R2 setup discs ar