SQL Server 2008 R2 install error

2013-12-25 20:40:22 Slp: Running Action: ExecuteBootstrapAfterExtensionsLoaded
2013-12-25 20:40:23 Slp: Error: Action "Microsoft.SqlServer.Configuration.BootstrapExtension.ExecuteWorkflowAction" threw an exception during execution.
2013-12-25 20:40:23 Slp: Microsoft.SqlServer.Setup.Chainer.Workflow.ActionExecutionException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. ---> Microsoft.SqlServer.Chainer.Infrastructure.ChainerInfrastructureException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information. ---> System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
2013-12-25 20:40:23 Slp:    at System.Reflection.Module._GetTypesInternal(StackCrawlMark& stackMark)
2013-12-25 20:40:23 Slp:    at System.Reflection.Assembly.GetTypes()
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Chainer.Infrastructure.ExtensionService.GetAttributedTypes(String extensionId, Type attributeType)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Chainer.Infrastructure.ExtensionService.GetAttributedTypes(Type attributeType)
2013-12-25 20:40:23 Slp:    --- End of inner exception stack trace ---
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Chainer.Infrastructure.ExtensionService.GetAttributedTypes(Type attributeType)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.WorkflowFactory.LoadWorkflowFromText(String workflowXmlText)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.WorkflowFactory.LoadWorkflow(XmlElement sequenceElement)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.WorkflowFactory.LoadWorkflowById(XmlElement sequencesElement, String workflowId)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Configuration.BootstrapExtension.ExecuteWorkflowAction.LoadWorkflowFromDatastoreXml()
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Configuration.BootstrapExtension.ExecuteWorkflowAction.ExecuteAction(String actionId)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Chainer.Infrastructure.Action.Execute(String actionId, TextWriter errorStream)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.ExecuteActionHelper(TextWriter statusStream, ISequencedAction actionToRun)
2013-12-25 20:40:23 Slp:    --- End of inner exception stack trace ---
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.ExecuteActionHelper(TextWriter statusStream, ISequencedAction actionToRun)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.ExecuteActionWithRetryHelper(WorkflowObject metaDb, ActionKey action, ActionMetadata actionMetadata, TextWriter statusStream)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.InvokeAction(WorkflowObject metabase, TextWriter statusStream)
2013-12-25 20:40:23 Slp:    at Microsoft.SqlServer.Setup.Chainer.Workflow.PendingActions.InvokeActions(WorkflowObject metaDb, TextWriter loggingStream)
2013-12-25 20:40:25 Slp: Received request to add the following file to Watson reporting: C:Documents and SettingsAdministratorLocal SettingsTemptmpE4.tmp
2013-12-25 20:40:25 Slp: The following is an exception stack listing the exceptions in outermost to innermost order
2013-12-25 20:40:25 Slp: Inner exceptions are being indented
2013-12-25 20:40:25 Slp:
2013-12-25 20:40:25 Slp: Exception type: Microsoft.SqlServer.Chainer.Infrastructure.ChainerInfrastructureException
2013-12-25 20:40:25 Slp:     Message:
2013-12-25 20:40:25 Slp:         Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
2013-12-25 20:40:25 Slp:     Stack:
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Chainer.Infrastructure.ExtensionService.GetAttributedTypes(Type attributeType)
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Setup.Chainer.Workflow.WorkflowFactory.LoadWorkflowFromText(String workflowXmlText)
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Setup.Chainer.Workflow.WorkflowFactory.LoadWorkflow(XmlElement sequenceElement)
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Setup.Chainer.Workflow.WorkflowFactory.LoadWorkflowById(XmlElement sequencesElement, String workflowId)
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Configuration.BootstrapExtension.ExecuteWorkflowAction.LoadWorkflowFromDatastoreXml()
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Configuration.BootstrapExtension.ExecuteWorkflowAction.ExecuteAction(String actionId)
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Chainer.Infrastructure.Action.Execute(String actionId, TextWriter errorStream)
2013-12-25 20:40:25 Slp:         at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.ExecuteActionHelper(TextWriter statusStream, ISequencedAction actionToRun)
2013-12-25 20:40:25 Slp:     Inner exception type: System.Reflection.ReflectionTypeLoadException
2013-12-25 20:40:25 Slp:         Message:
2013-12-25 20:40:25 Slp:                 Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
2013-12-25 20:40:25 Slp:         Stack:
2013-12-25 20:40:25 Slp:                 at System.Reflection.Module._GetTypesInternal(StackCrawlMark& stackMark)
2013-12-25 20:40:25 Slp:                 at System.Reflection.Assembly.GetTypes()
2013-12-25 20:40:25 Slp:                 at Microsoft.SqlServer.Chainer.Infrastructure.ExtensionService.GetAttributedTypes(String extensionId, Type attributeType)
2013-12-25 20:40:25 Slp:                 at Microsoft.SqlServer.Chainer.Infrastructure.ExtensionService.GetAttributedTypes(Type attributeType)