Just add a launch prerequisite for .NET 4.5 -- it's usually there, and if not it can be easily installed. This is mostly an issue on old Windows Server systems, and in that case the admin will likely want to decide how to proceed.

ext/installfiles/windows/ZeroTier One.aip

@@ -9,6 +9,8 @@
     <ROW Property="AI_EXTERNALUIUNINSTALLERNAME" MultiBuildValue="DefaultBuild:aiui"/>
     <ROW Property="AI_PREDEF_LCONDS_PROPS" Value="AI_DETECTED_DOTNET_VERSION"/>
     <ROW Property="AI_PRODUCTNAME_ARP" Value="ZeroTier One"/>
+    <ROW Property="AI_REQUIRED_DOTNET_DISPLAY" MultiBuildValue="DefaultBuild:4.5" ValueLocId="-"/>
+    <ROW Property="AI_REQUIRED_DOTNET_VERSION" MultiBuildValue="DefaultBuild:4.5" ValueLocId="-"/>
     <ROW Property="AI_UNINSTALLER" Value="msiexec.exe"/>
     <ROW Property="ALLUSERS" Value="1"/>
     <ROW Property="ARPCOMMENTS" Value="This installer database contains the logic and data required to install [|ProductName]."/>
@@ -24,7 +26,7 @@
     <ROW Property="CTRLS" Value="2"/>
     <ROW Property="MSIFASTINSTALL" MultiBuildValue="DefaultBuild:2"/>
     <ROW Property="Manufacturer" Value="ZeroTier, Inc."/>
-    <ROW Property="ProductCode" Value="1033:{1D75367B-40EC-408B-848B-3D147C9A2175} " Type="16"/>
+    <ROW Property="ProductCode" Value="1033:{E517BA79-1770-4556-B7A4-622434A9982B} " Type="16"/>
     <ROW Property="ProductLanguage" Value="1033"/>
     <ROW Property="ProductName" Value="ZeroTier One"/>
     <ROW Property="ProductVersion" Value="1.1.0" Type="32"/>
@@ -42,7 +44,7 @@
     <ROW Property="WindowsTypeNTDisplay" MultiBuildValue="DefaultBuild:Windows 2000, Windows XP x86, Windows Server 2003 x86" ValueLocId="-"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.MsiDirsComponent">
-    <ROW Directory="APPDIR" Directory_Parent="TARGETDIR" DefaultDir="APPDIR:." IsPseudoRoot="1" DirectoryOptions="3"/>
+    <ROW Directory="APPDIR" Directory_Parent="TARGETDIR" DefaultDir="APPDIR:." IsPseudoRoot="1" DirectoryOptions="2"/>
     <ROW Directory="CommonAppDataFolder" Directory_Parent="TARGETDIR" DefaultDir="COMMON~1|CommonAppDataFolder" IsPseudoRoot="1"/>
     <ROW Directory="One_Dir" Directory_Parent="ZeroTier_Dir" DefaultDir="One"/>
     <ROW Directory="ProgramFilesFolder" Directory_Parent="TARGETDIR" DefaultDir="PROGRA~1|ProgramFilesFolder" IsPseudoRoot="1"/>
@@ -150,7 +152,6 @@
     <ROW Name="SoftwareDetector.dll" SourcePath="&lt;AI_CUSTACTS&gt;SoftwareDetector.dll"/>
     <ROW Name="aicustact.dll" SourcePath="&lt;AI_CUSTACTS&gt;aicustact.dll"/>
     <ROW Name="chainersupport.dll" SourcePath="&lt;AI_CUSTACTS&gt;chainersupport.dll"/>
-    <ROW Name="dotNetFx45_Full_setup.exe" SourcePath="dotNetFx45_Full_setup.exe"/>
     <ROW Name="msichainer.exe" SourcePath="&lt;AI_CUSTACTS&gt;msichainer.exe"/>
     <ROW Name="xmlCfg.dll" SourcePath="&lt;AI_CUSTACTS&gt;xmlCfg.dll"/>
   </COMPONENT>
@@ -231,7 +232,6 @@
     <ROW Action="SET_TARGETDIR_TO_APPDIR" Type="51" Source="TARGETDIR" Target="[APPDIR]"/>
     <ROW Action="TapDeviceRemove32" Type="3154" Source="zerotierone_x86.exe" Target="-D"/>
     <ROW Action="TapDeviceRemove64" Type="3154" Source="zerotierone_x64.exe" Target="-D"/>
-    <ROW Action="dotNetFx45_Full_setup.exe" Type="66" Source="dotNetFx45_Full_setup.exe" Target="/q /norestart"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.MsiEmbeddedChainerComponent">
     <ROW MsiEmbeddedChainer="msichainer.exe" Condition="VersionMsi &gt;= &quot;4.05&quot;" CommandLine="[AI_CHAINER_CMD_LINE]" Source="msichainer.exe" Type="2"/>
@@ -260,7 +260,6 @@
     <ROW Action="AI_DATA_SETTER_2" Condition="(VersionNT &gt;= 501) AND (REMOVE &lt;&gt; &quot;ALL&quot;)" Sequence="5801"/>
     <ROW Action="AI_FwUninstall" Condition="(VersionNT &gt;= 501) AND (REMOVE=&quot;ALL&quot;)" Sequence="1702"/>
     <ROW Action="AI_DATA_SETTER_3" Condition="(VersionNT &gt;= 501) AND (REMOVE=&quot;ALL&quot;)" Sequence="1701"/>
-    <ROW Action="dotNetFx45_Full_setup.exe" Condition="( NOT Installed ) AND ( (AI_DETECTED_DOTNET_VERSION &lt; &quot;4.5&quot;) )" Sequence="6401"/>
     <ROW Action="AI_DetectSoftware" Sequence="101"/>
   </COMPONENT>
   <COMPONENT cid="caphyon.advinst.msicomp.MsiInstallUISequenceComponent">
@@ -276,6 +275,7 @@
     <ROW Condition="( Version9X OR ( NOT VersionNT64 ) OR ( VersionNT64 AND ((VersionNT64 &lt;&gt; 502) OR (((VersionNT64 = 502) AND (ServicePackLevel &gt;= 1)) OR (MsiNTProductType &lt;&gt; 1))) AND ((VersionNT64 &lt;&gt; 502) OR (((VersionNT64 = 502) AND (ServicePackLevel &lt;&gt; 1)) OR (MsiNTProductType &lt;&gt; 1))) AND ((VersionNT64 &lt;&gt; 502) OR (((VersionNT64 = 502) AND (ServicePackLevel &lt;&gt; 2)) OR (MsiNTProductType &lt;&gt; 1))) AND ((VersionNT64 &lt;&gt; 502) OR ((VersionNT64 = 502) AND ((MsiNTProductType = 1) OR (ServicePackLevel &gt;= 1)))) AND ((VersionNT64 &lt;&gt; 502) OR ((VersionNT64 = 502) AND ((MsiNTProductType = 1) OR (ServicePackLevel &lt;&gt; 1)))) AND ((VersionNT64 &lt;&gt; 502) OR ((VersionNT64 = 502) AND ((MsiNTProductType = 1) OR (ServicePackLevel &lt;&gt; 2)))) ) )" Description="[ProductName] cannot be installed on the following Windows versions: [WindowsTypeNT64Display]" DescriptionLocId="AI.LaunchCondition.NoSpecificNT64" IsPredefined="true" Builds="DefaultBuild"/>
     <ROW Condition="( Version9X OR VersionNT64 OR ( VersionNT AND ((VersionNT &lt;&gt; 500) OR ((VersionNT = 500) AND (ServicePackLevel &gt;= 1))) AND ((VersionNT &lt;&gt; 500) OR ((VersionNT = 500) AND (ServicePackLevel &lt;&gt; 1))) AND ((VersionNT &lt;&gt; 500) OR ((VersionNT = 500) AND (ServicePackLevel &lt;&gt; 2))) AND ((VersionNT &lt;&gt; 500) OR ((VersionNT = 500) AND (ServicePackLevel &lt;&gt; 3))) AND ((VersionNT &lt;&gt; 500) OR ((VersionNT = 500) AND (ServicePackLevel &lt;&gt; 4))) AND (((VersionNT &lt;&gt; 501) OR ((VersionNT = 501) AND (ServicePackLevel &gt;= 1))) OR VersionNT64) AND (((VersionNT &lt;&gt; 501) OR ((VersionNT = 501) AND (ServicePackLevel &lt;&gt; 1))) OR VersionNT64) AND (((VersionNT &lt;&gt; 501) OR ((VersionNT = 501) AND (ServicePackLevel &lt;&gt; 2))) OR VersionNT64) AND (((VersionNT &lt;&gt; 501) OR ((VersionNT = 501) AND (ServicePackLevel &lt;&gt; 3))) OR VersionNT64) AND (((VersionNT &lt;&gt; 502) OR ((VersionNT = 502) AND (ServicePackLevel &gt;= 1))) OR VersionNT64) AND (((VersionNT &lt;&gt; 502) OR ((VersionNT = 502) AND (ServicePackLevel &lt;&gt; 1))) OR VersionNT64) AND (((VersionNT &lt;&gt; 502) OR ((VersionNT = 502) AND (ServicePackLevel &lt;&gt; 2))) OR VersionNT64) ) )" Description="[ProductName] cannot be installed on the following Windows versions: [WindowsTypeNTDisplay]" DescriptionLocId="AI.LaunchCondition.NoSpecificNT" IsPredefined="true" Builds="DefaultBuild"/>
     <ROW Condition="(VersionNT &lt;&gt; 400)" Description="[ProductName] cannot be installed on the following Windows versions: [WindowsTypeNT40Display]" DescriptionLocId="AI.LaunchCondition.NoNT40" IsPredefined="true" Builds="DefaultBuild"/>
+    <ROW Condition="AI_DETECTED_DOTNET_VERSION &gt;= AI_REQUIRED_DOTNET_VERSION" Description="[ProductName] cannot be installed on systems with .NET Framework version lower than [AI_REQUIRED_DOTNET_DISPLAY]." DescriptionLocId="AI.LaunchCondition.DotNET" IsPredefined="true" Builds="DefaultBuild"/>
     <ROW Condition="Privileged" Description="[ProductName] requires administrative privileges to install." DescriptionLocId="AI.LaunchCondition.Privileged" IsPredefined="true" Builds="DefaultBuild"/>
     <ROW Condition="VersionNT" Description="[ProductName] cannot be installed on [WindowsType9XDisplay]" DescriptionLocId="AI.LaunchCondition.No9X" IsPredefined="true" Builds="DefaultBuild"/>
   </COMPONENT>