got the whole day trying to install SQL Server 2008 Management Studio after first installing Visual Studio Product. It didn’t work when I many times followed the installation guide, error after error, I finally got it installed by this instruction:
The point is select “Perform a new installation of SQL Server 2008” on step 6.
(If you have already installed SQL Server 2008 Express with the Web Platform Installer)
As of March 4, 2010…
0. If you are using Server 2008, Install Windows PowerShell using these instructions: http://www.tech-recipes.com/rx/2521/windows_server_2008_install_windows_powershell/. Otherwise download and install it from here: http://technet.microsoft.com/en-ca/scriptcenter/dd772288.aspx
1. Download and run the SSME installer from http://www.microsoft.com/downloads/details.aspx?familyid=08e52ac2-1d62-45f6-9a4a-4b76a8564a2b&displaylang=en
2. Click Installation on the left side of the the wizard.
3. Select “New SQL Server stand-alone installation or add features to an existing installation“. Click OK.
4. On the Setup Support Files page, select Install.
5. On the Setup Support Rules page, click Next (the Windows Firewall warning is ok).
6. On the Installation Type page of the wizard, select “Perform a new installation of SQL Server 2008“, then click Next. (I realize that this is counter-intuitive, but if you select “Add features to an existing instance of SQL Server 2008″, you will be met with a greyed out pre-selected option to install the SQL Client Connectivity SDK, and you will not even see an option to install “Management Tools – Basic”.) You will see that SQLEXPRESS is recognized as an installed instance.
7. The Product Key screen is all greyed out with the “Specify a free edition” selected. Click Next.
8. Agree to the License Terms as usual. Click Next.
9. On the Feature Selection page, you will FINALLY have a blank checkbox next to “Management Tools – Basic”. Put a check in that box. SQL Client Connectivity SDK is selected and greyed out by default; so is the install location. Click Next.
10. Click Next on the Disk Space Requirements screen.
11. Check both boxes to send error info to Microsoft if you wish. I usually do so that they can make the product better.Click Next.
12. Click Next on Installation Rules page if your system passed.
13. Click Install on the Ready to Install page.
14. Hopefully you will see a “Management Tools – Basic Success” message on the Installation Progress page of the wizard. Click Next.
15. You should see a “Your SQL Server 2008 installation completed successfully” message on the Complete page. Click Close.I always like to reboot for good measure before and after installing any new software.
Hope this saves developers some headaches.
Cheers,
Rog
For more, follow this link.

Thanks man! That worked.