have you looked at the following file in the source tree? src\ext\NetFxExtension\wixlib\NetFx451.wxs
And the help doc is here: http://wixtoolset.org/documentation/manual/v3/howtos/redistributables_and_install_checks/check_for_dotnet.html The help doc does not mention 4.5.1 but the support was added to wix 3.8, as far as I can see. It has code that detects .Net 4.5.1 I have not used this to detect 4.5.1, but I do detect other versions of .Net without using a custom action. I detect if NetFx3 is installed as follows, but I do not try to detect a specific version of NetFx3: <util:RegistrySearch Id="RdpNetfx30_x64" Root="HKLM" Key="SOFTWARE\Microsoft\.NetFramework\v3.0" Variable="Netfx30_x64_Exists" Result="exists" /> The package is conditioned as follows: InstallCondition="NOT Netfx30_x64_Exists" -- View this message in context: http://windows-installer-xml-wix-toolset.687559.n2.nabble.com/How-to-compare-REG-DWORD-values-in-conditions-detect-NET-4-5-1-tp7590158p7592812.html Sent from the wix-users mailing list archive at Nabble.com. ------------------------------------------------------------------------------ Managing the Performance of Cloud-Based Applications Take advantage of what the Cloud has to offer - Avoid Common Pitfalls. Read the Whitepaper. http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk _______________________________________________ WiX-users mailing list WiX-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wix-users