OK I think that registers it

java/net/i2p/router/WinLauncher.java

@@ -2,10 +2,16 @@ package net.i2p.router;
 
 import java.io.*;
 import java.util.*;
+
+import net.i2p.app.ClientAppManager;
 import net.i2p.router.RouterLaunch;
 import net.i2p.router.Router;
+import net.i2p.update.UpdateManager;
+import net.i2p.update.UpdatePostProcessor;
 import net.i2p.util.SystemVersion;
 
+import static net.i2p.update.UpdateType.*;
+
 /**
  * Launches a router from %PROGRAMFILES%/I2P using configuration data in
  * %LOCALAPPDATA%/I2P..  Uses Java 9 APIs.
@@ -16,8 +22,9 @@ import net.i2p.util.SystemVersion;
  * router.pid - the pid of the java process.
  */
 public class WinLauncher extends WindowsUpdatePostProcessor {
+    WindowsUpdatePostProcessor wupp = new WindowsUpdatePostProcessor();
 
-    public static void main(String[] args) throws Exception {
+    public void main(String[] args) throws Exception {
         File programs = selectProgramFile();
 
         File home = selectHome();
@@ -35,10 +42,18 @@ public class WinLauncher extends WindowsUpdatePostProcessor {
 
         i2pRouter = new Router(System.getProperties());
 
+        UpdateManager upmgr = updateManagerClient();
+        if (upmgr != null) {
+            upmgr.register(this.wupp, ROUTER_SIGNED_SU3, 6);
+            upmgr.register(this.wupp, ROUTER_DEV_SU3, 6);
+        }else{
+            System.out.println("\t unable to register updates");
+        }
+
         i2pRouter.runRouter();
     }
 
-    private static File selectHome() { //throws Exception {
+    private File selectHome() { //throws Exception {
         if (SystemVersion.isWindows()) {
             File home = new File(System.getProperty("user.home"));
             File appData = new File(home, "AppData");
@@ -53,4 +68,18 @@ public class WinLauncher extends WindowsUpdatePostProcessor {
         }
     }
 
+    private UpdateManager updateManagerClient() {
+        ClientAppManager clmgr = i2pRouter.getContext().getCurrentContext().clientAppManager();
+        if (clmgr == null) {
+            return null;
+        }
+
+        UpdateManager upmgr = (UpdateManager) clmgr.getRegisteredApp(UpdateManager.APP_NAME);
+        if (upmgr == null) {
+            return null;
+        }
+
+        return upmgr;
+    }
+
 }

java/net/i2p/router/WindowsUpdatePostProcessor.java

@@ -2,23 +2,28 @@ package net.i2p.router;
 
 import java.io.*;
 import java.util.*;
+import java.util.concurrent.TimeUnit;
 
 import static net.i2p.update.UpdateType.*;
 import net.i2p.update.UpdateType;
+import net.i2p.update.UpdatePostProcessor;
 import net.i2p.util.SystemVersion;
 
 import java.lang.ProcessBuilder;
 import java.lang.Process;
 import java.lang.InterruptedException;
 
-public class WindowsUpdatePostProcessor {
-    protected static Router i2pRouter = null;
+public class WindowsUpdatePostProcessor implements UpdatePostProcessor {
+    protected Router i2pRouter = null;
     public void updateDownloadedandVerified(UpdateType type, int fileType, String version, File file) throws IOException {
         if (fileType == 6) {
             if (runUpdate(file)) {
+                try {
                     if (shutdownGracefullyAndRerun()) {
                     }
-            } else {
+                } catch (InterruptedException ie) {
+                    i2pRouter.cancelGracefulShutdown();
+                }
             }
         }
     }
@@ -45,10 +50,11 @@ public class WindowsUpdatePostProcessor {
         return true;
     }
 
-    private boolean shutdownGracefullyAndRerun() {
+    private boolean shutdownGracefullyAndRerun() throws InterruptedException {
         i2pRouter.shutdownGracefully();
         ProcessBuilder pb = new ProcessBuilder("cmd", "/c", selectProgramFile().getAbsolutePath());
         while (i2pRouter.gracefulShutdownInProgress()) {
+            TimeUnit.MILLISECONDS.sleep(125);
         }
         if (i2pRouter.isFinalShutdownInProgress()) {
             try {
@@ -62,7 +68,7 @@ public class WindowsUpdatePostProcessor {
         return false;
     }
 
-    protected static File selectProgramFile() {
+    protected File selectProgramFile() {
         if (SystemVersion.isWindows()) {
             File jrehome = new File(System.getProperty("java.home"));
             File programs = jrehome.getParentFile();
@@ -74,7 +80,7 @@ public class WindowsUpdatePostProcessor {
         }
     }
 
-    protected static File selectProgramFileExe() {
+    protected File selectProgramFileExe() {
 	File pfpath = selectProgramFile();
         if (SystemVersion.isWindows()) {
             File app = new File(pfpath, "I2P.exe");