diff --git a/java/net/i2p/router/WinLauncher.java b/java/net/i2p/router/WinLauncher.java
index 7c4682b..61fe6c2 100644
--- a/java/net/i2p/router/WinLauncher.java
+++ b/java/net/i2p/router/WinLauncher.java
@@ -97,12 +97,14 @@ public class WinLauncher {
 
     private static File selectHome() { // throws Exception {
         String path_override = System.getenv("I2P_CONFIG");
-        File path = new File(path_override);
-        if (path.exists()) {
-            if (path.isDirectory())
-                return path.getAbsoluteFile();
-            else
-                throw new RuntimeException("I2P is not a directory: " + path);
+        if (path_override != null) {
+            File path = new File(path_override);
+            if (path != null && path.exists()) {
+                if (path.isDirectory())
+                    return path.getAbsoluteFile();
+                else
+                    throw new RuntimeException("I2P_CONFIG is not a directory: " + path);
+            }
         }
         if (SystemVersion.isWindows()) {
             File home = new File(System.getProperty("user.home"));
@@ -122,12 +124,14 @@ public class WinLauncher {
 
     private static File selectProgramFile() {
         String path_override = System.getenv("I2P");
-        File path = new File(path_override);
-        if (path.exists()) {
-            if (path.isDirectory())
-                return path.getAbsoluteFile();
-            else
-                throw new RuntimeException("I2P is not a directory: " + path);
+        if (path_override != null) {
+            File path = new File(path_override);
+            if (path.exists()) {
+                if (path.isDirectory())
+                    return path.getAbsoluteFile();
+                else
+                    throw new RuntimeException("I2P is not a directory: " + path);
+            }
         }
         if (SystemVersion.isWindows()) {
             File jrehome = new File(System.getProperty("java.home"));