Here is a list of steps to try out as well:
1. Make sure you have administrative rights on the computer
2. Download and install Microsoft .Net Framework 3.5 SP1 1 for 32-bit or 64-bit based on your OS architecture:
http://www.microsoft.com/downloads/details.aspx?FamilyId=AB99342F-5D1A-413D-8319-81DA479AB0D7&displaylang=en3. Download and install Windows Installer 4.5 for 32-bit or 64-bit based on your OS architecture:
http://support.microsoft.com/kb/9422884. Check if the computer has Visual Studio 2008 or the prerelease version of SQL Server 2008 installed. If the version of your Visual Studio is 2008, you need to install Visual Studio 2008 SP1. For more information, please see
http://support.microsoft.com/kb/956139.
5. Download SQL Server 2008 Express Edition Service Pack 1 for 32-bit or 64-bit based on your OS architecture and install it:
http://www.microsoft.com/downloads/details.aspx?familyid=01AF61E6-2F63-4291-BCAD-FD500F6027FF&displaylang=enIf it still fails, please provide the error messages logged into the setup log files which are located in the %Program files%\Microsoft sql server\100\Setup bootstrap\Log\ folder. For more information about how to View and Read SQL Server Setup Log Files, please see
http://msdn.microsoft.com/en-us/library/ms143702.aspx.