Installation failed while installing SQL Server 2008

Installing the Default instance of SQL Server 2008 R2 Express with Tools on a Windows 7 64bit failed with error:

Error Says:

Rule “Same architecture installation” failed.

The CPU architecture of installing feature(s) is different than the instance specified. To continue, add features to this instance with the same architecture.


Cause might be:
As the error clearly says, that some installation with the same architecture already exists, You need to remove that installation in order to install a new one.


Un-installation of a previously installed Default instance of SQL Server 2008 64-bit was not clean.

You need to make sure that no other version of SQL Server is installed before.

To Uninstall the previously installed instance follow the steps:

  1. Open Add or Remove Programs from the control panel


    Click Start, click Run, type “appwiz.cpl”, and then press ENTER.


  1. In the list of installed programs, click Microsoft SQL Server 2008, and then click Uninstall.
    (No need to uninstall other programs like Microsoft SQL Server browser etc.)


  1. Follow the instructions that appear on the screen to uninstall SQL Server 2008.

Now Try installing the SQL Server 2008 R2 Express with Tools and it should work fine.