Do you have Windows 7 64Bit and you are trying to install SQL Server 2008 Management Tools and cannot?

{Programming} & Life has the long answer at this link

Here is the short answer from the same site.

FIX – INSTALL BACKWARDS!

So that’s the logic, install everything backwards:

First the SQLManagementStudio_x64_ENU.exe to install your tools, and then SQLEXPR_x64_ENU.exe to install your database services. Or perhaps if you are happy with an all in one package, go for this guy – Microsoft® SQL Server® 2008 Express with Tools it’ll probably save you a lifetime of headaches. Don’t try to be tricky like me and get separate installs.