This one was tricky [at least from my perspective, since I am not a SQL expert ]. I wasted a lot of my time today, and hence documenting this effort so that it might help a poor soul some day. Your mileage may vary. Please take all cautions that you normally would while dealing with SQL.

Problem Scenario

1. Installed SQL Express
2. Installed SQL Server 2008 Management Studio Express
3. Installed SQL Server 2008 R2

ONLY to find that Management Tools – Complete was missing from my setup. Even worse, it was greyed out. So, running setup again and simply checking this Check box was not an option.

Resolution

    I tried to uninstall SQL Express, but couldn’t find it my Add/Remove programs.
    Couldn’t remove it from the SQL Server installation Center either.
    Hence, decided to upgrade using Maintenance option – Edition Upgrade, and upgraded my SQL Express.

    Once the upgrade happened successfully, started the SQL Server setup again.
    Tried setup again, and this time selected… Installation –> New Installation. In the Installation Type, select Add Features… select the instance, and click Next.

    In the feature selection, you should ideally get Management Tools – Complete option which wouldn’t be greyed out now. Complete the setup and you’re done.
    You can also Uninstall SQL Express by starting Add/Remove programs –> Microsoft SQL Server 2008 R2 (64-bit) and uninstall. You’ll be prompted with a screen, where you should select Remove. Follow the wizard, till you get option to remove your SQL Express.

Hope this helps,
Rahul