I always use sql server 2008, and now my new projects need 2005. I searched solution to create scripts on 2008 and use it on 2005, however their mdf file on their 2005 cannnot be attached to my 2008. So, I tried to install 2005 at the same time. I have also tried to give the instance of 2005 a name instead of using default instance, still cannot find that instance. Can I use 2008 management studio to open 2005 instance? or do you know how to attach 2005 mdf file on my 2008? Why I cannot even attach that file?