Here is the solution which worked for me using <util:XmlFile
<Component Id="cmp5F6F9B35A372943520CC8D5ABDE2F507" Directory="dirCFCE6D07D3330FE628276777F0488B18" Guid="{3AFB6DE8-D43E-4EC3-BC10-251EABFE3DD0}"> <File Id="fil24F01DF9AB46C9205A3E021D5E98A3CF" KeyPath="yes" Source="$(var.SCBUDirect.B2CWeb.ProjectDir)Web.Prod.Web1.config" > <CopyFile Id="KCopy_ConnPROD" DestinationProperty="DestFilesWebsiteFolder" DestinationName="Web.config" /> </File> <Condition> </Condition> <util:XmlFile Id='name' Action="setValue" Sequence="1" File="[#fil793B13C959C0F19A591946A8F8A1CF6E]" ElementPath="//configuration/system.webServer/httpProtocol/customHeaders/add[\[]@name='X- ServerID'[\]]" Name="value" SelectionLanguage="XPath" Value='[ComputerName]'/> </Component> -- View this message in context: http://windows-installer-xml-wix-toolset.687559.n2.nabble.com/Change-content-of-Config-file-after-installation-tp7584789p7584809.html Sent from the wix-users mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Own the Future-Intel® Level Up Game Demo Contest 2013 Rise to greatness in Intel's independent game demo contest. Compete for recognition, cash, and the chance to get your game on Steam. $5K grand prize plus 10 genre and skill prizes. Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d _______________________________________________ WiX-users mailing list WiX-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wix-users