TemporaryDirectory will deleted at the end of process, Path of NSIS is besite of base directory.

Creator/Helper/TemporaryDirectory.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Threading;
+
+namespace KattekerCreator.Helper
+{
+    public class TemporaryDirectory : IDisposable
+    {
+        public string Path { get; }
+
+        public TemporaryDirectory(string path)
+        {
+            Path = path;
+        }
+
+        void IDisposable.Dispose()
+        {
+            try
+            {
+                Thread.Sleep(100);
+                System.IO.Directory.Delete(Path, true);
+            }
+            catch
+            {
+                //ignore.
+            }
+        }
+    }
+}

Creator/Helper/Utils.cs

@@ -19,7 +19,7 @@ namespace KattekerCreator.Helper
             return false;
         }
 
-        public static string CreateTempDirectory()
+        public static TemporaryDirectory CreateTempDirectory()
         {
             string result;
             do
@@ -29,7 +29,7 @@ namespace KattekerCreator.Helper
             } while (Directory.Exists(result));
 
             Directory.CreateDirectory(result);
-            return result;
+            return new TemporaryDirectory(result);
         }
 
         public static bool IsFilesizeWrong(string filename)