diff --git a/IPA.Injector/Backups/BackupManager.cs b/IPA.Injector/Backups/BackupManager.cs
new file mode 100644
index 00000000..368a50a4
--- /dev/null
+++ b/IPA.Injector/Backups/BackupManager.cs
@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+
+namespace IPA.Injector.Backups
+{
+    public class BackupManager
+    {
+        public static BackupUnit FindLatestBackup(string dir)
+        {
+            new DirectoryInfo(dir).Create();
+            return new DirectoryInfo(dir)
+                .GetDirectories()
+                .OrderByDescending(p => p.Name)
+                .Select(p => BackupUnit.FromDirectory(p, dir))
+                .FirstOrDefault();
+        }
+
+        public static bool HasBackup(string dir)
+        {
+            return FindLatestBackup(dir) != null;
+        }
+    }
+}
diff --git a/IPA.Injector/Backups/BackupUnit.cs b/IPA.Injector/Backups/BackupUnit.cs
new file mode 100644
index 00000000..ad7c6e5f
--- /dev/null
+++ b/IPA.Injector/Backups/BackupUnit.cs
@@ -0,0 +1,104 @@
+using IPA.Logging;
+using IPA.Utilities;
+using System;
+using System.Collections.Generic;
+using System.Collections.Specialized;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace IPA.Injector.Backups
+{
+    /// <summary>
+    /// A unit for backup. WIP.
+    /// </summary>
+    public class BackupUnit
+    {
+        public string Name { get; private set; }
+        
+        private DirectoryInfo _BackupPath;
+        private HashSet<string> _Files = new HashSet<string>();
+        private FileInfo _ManifestFile;
+        private static string _ManifestFileName = "$manifest$.txt";
+        
+        public BackupUnit(string dir) : this(dir, DateTime.Now.ToString("yyyy-MM-dd_h-mm-ss"))
+        {
+        }
+
+        private BackupUnit(string dir, string name)
+        {
+            Name = name;
+            _BackupPath = new DirectoryInfo(Path.Combine(dir, Name));
+            _ManifestFile = new FileInfo(Path.Combine(_BackupPath.FullName, _ManifestFileName));
+        }
+        
+        public static BackupUnit FromDirectory(DirectoryInfo directory, string dir)
+        {
+            var unit = new BackupUnit(dir, directory.Name);
+
+            // Read Manifest
+            if (unit._ManifestFile.Exists)
+            {
+                string manifest = File.ReadAllText(unit._ManifestFile.FullName);
+                foreach (var line in manifest.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries))
+                    unit._Files.Add(line);
+            }
+            else
+            {
+                foreach (var file in directory.GetFiles("*", SearchOption.AllDirectories))
+                {
+                    if (file.Name == _ManifestFileName) continue;
+                    var relativePath = file.FullName.Substring(directory.FullName.Length + 1);
+                    unit._Files.Add(relativePath);
+                }
+            }
+
+            return unit;
+        }
+
+        public void Add(string file)
+        {
+            Add(new FileInfo(file));
+        }
+
+        internal void Delete()
+        {
+            _BackupPath.Delete(true);
+        }
+
+        /// <summary>
+        /// Adds a file to the list of changed files and backups it.
+        /// </summary>
+        /// <param name="path"></param>
+        public void Add(FileInfo file)
+        {
+            var relativePath = LoneFunctions.GetRelativePath(file.FullName, Environment.CurrentDirectory);
+            var backupPath = new FileInfo(Path.Combine(_BackupPath.FullName, relativePath));
+            
+            // Copy over
+            backupPath.Directory.Create();
+            if (file.Exists)
+            {
+                file.CopyTo(backupPath.FullName);
+            }
+            else
+            {
+                // Make empty file
+                backupPath.Create().Close();
+            }
+
+            if (!_Files.Contains(relativePath))
+            {
+                if (!File.Exists(_ManifestFile.FullName))
+                    _ManifestFile.Create().Close();
+                var stream = _ManifestFile.AppendText();
+                stream.WriteLine(relativePath);
+                stream.Close();
+
+                // Add to list
+                _Files.Add(relativePath);
+            }
+        }
+
+    }
+}
diff --git a/IPA.Injector/IPA.Injector.csproj b/IPA.Injector/IPA.Injector.csproj
index 4cdf91ab..8b93e097 100644
--- a/IPA.Injector/IPA.Injector.csproj
+++ b/IPA.Injector/IPA.Injector.csproj
@@ -52,6 +52,8 @@
     </Reference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Backups\BackupManager.cs" />
+    <Compile Include="Backups\BackupUnit.cs" />
     <Compile Include="Bootstrapper.cs" />
     <Compile Include="ConsoleWindow.cs" />
     <Compile Include="Injector.cs" />
diff --git a/IPA.Injector/Injector.cs b/IPA.Injector/Injector.cs
index 4c0d7fe0..1b3e2a73 100644
--- a/IPA.Injector/Injector.cs
+++ b/IPA.Injector/Injector.cs
@@ -1,4 +1,5 @@
 using Harmony;
+using IPA.Injector.Backups;
 using IPA.Loader;
 using IPA.Logging;
 using Mono.Cecil;
@@ -50,6 +51,12 @@ namespace IPA.Injector
         {
             var cAsmName = Assembly.GetExecutingAssembly().GetName();
 
+            loader.Debug("Finding backup");
+            var backupPath = Path.Combine(Environment.CurrentDirectory, "IPA","Backups","Beat Saber");
+            var bkp = BackupManager.FindLatestBackup(backupPath);
+            if (bkp == null)
+                loader.Warn("No backup found! Was BSIPA installed using the installer?");
+
             loader.Debug("Ensuring patch on UnityEngine.CoreModule exists");
             #region Insert patch into UnityEngine.CoreModule.dll
             var unityPath = Path.Combine(Environment.CurrentDirectory, "Beat Saber_Data", "Managed", "UnityEngine.CoreModule.dll");
@@ -110,6 +117,7 @@ namespace IPA.Injector
 
             if (modified)
             {
+                bkp?.Add(unityPath);
                 unityAsmDef.Write(unityPath);
             }
             #endregion
@@ -119,7 +127,7 @@ namespace IPA.Injector
             var ascPath = Path.Combine(Environment.CurrentDirectory, "Beat Saber_Data", "Managed", "Assembly-CSharp.dll");
             
             var ascModule = VirtualizedModule.Load(ascPath);
-            ascModule.Virtualize(cAsmName);
+            ascModule.Virtualize(cAsmName, () => bkp?.Add(ascPath));
             #endregion
         }
 
diff --git a/IPA/Program.cs b/IPA/Program.cs
index e6edc75b..69f4d81e 100644
--- a/IPA/Program.cs
+++ b/IPA/Program.cs
@@ -255,8 +255,8 @@ namespace IPA
                         backup,
                         null, false);
 
-                    backup.Add(context.AssemblyFile);
-                    backup.Add(context.EngineFile);
+                    //backup.Add(context.AssemblyFile);
+                    //backup.Add(context.EngineFile);
                 }
 
                 #region Create Plugin Folder