Power Pivot installed fine however when

Power Pivot installed fine however when I tried to open it I got the error below. All .net framework updates through windows update are installed. Name: From: file:///C:/Program Files (x86)/Microsoft Analysis Services/AS Excel Client/10/Microsoft.AnalysisServices.Modeler.FieldList.vsto ************** Exception Text ************** System.Configuration.ConfigurationErrorsException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException: Unexpected end of file while parsing Comment has occurred. Line 187, position 1. (C:\Windows\Microsoft.NET\Framework\v2.0.50727\Config\machine.config line 187) ---> System.Xml.XmlException: Unexpected end of file while parsing Comment has occurred. Line 187, position 1. at System.Xml.XmlTextReaderImpl.Throw(Exception e) at System.Xml.XmlTextReaderImpl.Throw(String res, String arg) at System.Xml.XmlTextReaderImpl.ParseCDataOrComment(XmlNodeType type, Int32& outStartPos, Int32& outEndPos) at System.Xml.XmlTextReaderImpl.ParseCDataOrComment(XmlNodeType type) at System.Xml.XmlTextReaderImpl.ParseComment() at System.Xml.XmlTextReaderImpl.ParseElementContent() at System.Xml.XmlTextReaderImpl.Read() at System.Xml.XmlTextReader.Read() at System.Xml.XmlTextReaderImpl.Skip() at System.Xml.XmlTextReader.Skip() at System.Configuration.XmlUtil.StrictSkipToNextElement(ExceptionAction action) at System.Configuration.BaseConfigurationRecord.ScanSectionsRecursive(XmlUtil xmlUtil, String parentConfigKey, Boolean inLocation, String locationSubPath, OverrideModeSetting overrideMode, Boolean skipInChildApps) at System.Configuration.BaseConfigurationRecord.ScanSections(XmlUtil xmlUtil) at System.Configuration.BaseConfigurationRecord.InitConfigFromFile() --- End of inner exception stack trace --- at System.Configuration.ConfigurationSchemaErrors.ThrowIfErrors(Boolean ignoreLocal) at System.Configuration.BaseConfigurationRecord.ThrowIfParseErrors(ConfigurationSchemaErrors schemaErrors) at System.Configuration.BaseConfigurationRecord.ThrowIfInitErrors() at System.Configuration.ClientConfigurationSystem.EnsureInit(String configKey) --- End of inner exception stack trace --- at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.GetManifests(TimeSpan timeout) at Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.InstallAddIn()