I have a problem with installing SQL Server 2008 R2 Express.
On my computer, I have installed VC# and VWebdev 2010 express. It included SQL Server 2008 Express inside.
After that, I did an upgrade to SQL Server 2008 R2 Express.
The consequence is I can't connect to a local server itself. So, I uninstall all of SQLServer products and reinstall again. Then an error message pops up on my screen which is pasted on the end of this question.
My computer runs on Win7 x64. SQL Server installer is a 64-bit version. My System.dll, which I think a root of this problem, assembly is 2.0.0.0 version.
The error message:
System.Configuration.ConfigurationErrorsException: An error occurred creating the configuration section handler for userSettings/Microsoft.SqlServer.Configuration.LandingPage.Properties.Settings: Could not load file or assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The system cannot find the file specified. (C:\Users\BenZ\AppData\Local\Microsoft_Corporation\LandingPage.exe_StrongName_ryspccglaxmt4nhllj5z3thycltsvyyx\10.0.0.0\user.config line 5) ---> System.IO.FileNotFoundException: Could not load file or assembly 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The system cannot find the file specified. File name: 'System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' at System.Configuration.TypeUtil.GetTypeWithReflectionPermission(IInternalConfigHost host, String typeString, Boolean throwOnError) at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory.Init(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord) at System.Configuration.RuntimeConfigurationRecord.RuntimeConfigurationFactory.InitWithRestrictedPermissions(RuntimeConfigurationRecord configRecord, FactoryRecord factoryRecord) at System.Configuration.RuntimeConfigurationRecord.CreateSectionFactory(FactoryRecord factoryRecord) at System.Configuration.BaseConfigurationRecord.FindAndEnsureFactoryRecord(String configKey, Boolean& isRootDeclaredHere)