I have made it that each Instance has its own login info

MultiMC/GTKGUI/GTKGUIManager.cs

@@ -137,5 +137,9 @@ public ITextInputDialog TextInputDialog(string message, string text = "")
 		{
 			return new TextInputDialog(message,text,mainWindow);
 		}
+		public IImportLoginInfoDialog ImportLoginInfoDialog()
+                {
+                        throw new NotImplementedException();
+                }
 	}
 }

MultiMC/GTKGUI/MainWindow.cs

@@ -269,6 +269,11 @@ void OnCheckUpdatesClicked(object sender, EventArgs e)
 				CheckUpdatesClicked(this, EventArgs.Empty);
 		}
 
+        void OnImportInstLoginInfoClicked(object sender, EventArgs e)
+        {
+            if (ImportInstLoginInfoClicked != null)
+                ImportInstLoginInfoClicked(this, EventArgs.Empty);
+        }
 
 		void OnHelpClicked(object sender, EventArgs e)
 		{
@@ -325,6 +330,7 @@ void OnViewInstFolderClicked(object sender, EventArgs e)
 				ViewInstFolderClicked(this, new InstActionEventArgs(SelectedInst));
 		}
 
+
 		void OnDeleteClicked(object sender, EventArgs e)
 		{
 			if (DeleteInstClicked != null)
@@ -422,6 +428,8 @@ public IList<Instance> InstanceList
 
 		public event EventHandler CheckUpdatesClicked;
 
+        public event EventHandler ImportInstLoginInfoClicked;
+
 		public event EventHandler HelpClicked;
 
 		public event EventHandler AboutClicked;
@@ -438,6 +446,8 @@ public IList<Instance> InstanceList
 
 		public event EventHandler<InstActionEventArgs> ViewInstFolderClicked;
 
+
+
 		public event EventHandler<InstActionEventArgs> DeleteInstClicked;
 
 		public event EventHandler<InstActionEventArgs> RemoveOpenALClicked;

MultiMC/GUI/IGUIManager.cs

@@ -32,6 +32,8 @@ public interface IGUIManager
 
 		IEditModsDialog EditModsDialog(Instance inst);
 
+        IImportLoginInfoDialog ImportLoginInfoDialog();
+
 		ILoginDialog LoginDialog(string errMsg = null);
 
 		IDialog DeleteDialog();

MultiMC/GUI/IImportLoginInfoDialog.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace MultiMC.GUI
+{
+    public interface IImportLoginInfoDialog : IDialog
+    {
+
+    }
+}

MultiMC/GUI/IMainWindow.cs

@@ -45,8 +45,9 @@ public interface IMainWindow : IWindow
 
 		event EventHandler HelpClicked;
 		event EventHandler AboutClicked;
-
-
+
+                event EventHandler ImportInstLoginInfoClicked;
+
 		event EventHandler<InstActionEventArgs> InstanceLaunched;
 
 		event EventHandler<InstActionEventArgs> ChangeIconClicked;

MultiMC/Instance.cs

@@ -79,6 +79,32 @@ public static Instance[] LoadInstances(string instDir)
 			}
 			return (Instance[])instList.ToArray(typeof(Instance));
 		}
+        public static String[] LoadInstancesNames(string instDir)
+        {
+            if (!Directory.Exists(instDir))
+            {
+                return new String[0];
+            }
+
+            ArrayList instList = new ArrayList();
+            foreach (string dir in Directory.GetDirectories(instDir))
+            {
+                Console.WriteLine("Loading instance from " + dir + "...");
+                Instance inst = null;
+                try
+                {
+                    inst = LoadInstance(dir);
+                }
+                catch (InvalidInstanceException e)
+                {
+                    Console.WriteLine(e.Message);
+                }
+
+                if (inst != null)
+                    instList.Add(inst.Name);
+            }
+            return (string[])instList.ToArray(typeof(string));
+        }
 
 		/// <summary>
 		/// Loads the instance from the specified directory.
@@ -376,6 +402,7 @@ public string RootDir
 			}
 		}
 
+
 		/// <summary>
 		/// The directory where mods will be stored
 		/// </summary>

MultiMC/Main.cs

@@ -66,7 +66,7 @@ public Main()
 
 			MainWindow.SettingsClicked += SettingsClicked;
 			MainWindow.CheckUpdatesClicked += UpdateClicked;
-
+            MainWindow.ImportInstLoginInfoClicked += ImportInstLoginInfoClicked;
 			MainWindow.AboutClicked += AboutClicked;
 
 			// Instance context menu
@@ -79,7 +79,7 @@ public Main()
 			MainWindow.EditModsClicked += EditModsClicked;
 			MainWindow.RebuildJarClicked += RebuildClicked;
 			MainWindow.ViewInstFolderClicked += ViewInstFolderClicked;
-
+            
 			MainWindow.DeleteInstClicked += DeleteInstClicked;
 			// on linux, provide the possiblity to nuke OpenAL libs
 			if(OSUtils.OS == OSEnum.Linux)
@@ -348,8 +348,8 @@ void ViewFolderClicked(object sender, EventArgs e)
 		{
 			string instDir = Path.GetFullPath(AppSettings.Main.InstanceDir);
 
-			if (!Directory.Exists(instDir))
-				Directory.CreateDirectory(instDir);
+            if (!Directory.Exists(instDir))
+                Directory.CreateDirectory(instDir);
 			Process.Start(instDir);
 		}
 
@@ -378,7 +378,26 @@ void SettingsClicked(object sender, EventArgs e)
 			{
 				DownloadNewVersion();
 			}
+
 		}
+
+        void ImportInstLoginInfoClicked(object sender, EventArgs e)
+        {
+            IImportLoginInfoDialog importLoginInfoDlg = GUIManager.Main.ImportLoginInfoDialog();
+            importLoginInfoDlg.ShowInTaskbar = false;
+
+            importLoginInfoDlg.Response += (o, args) =>
+            {
+                if (args.Response == DialogResponse.OK)
+                importLoginInfoDlg.Close();
+                if (args.Response == DialogResponse.Cancel)
+                importLoginInfoDlg.Close();
+            };
+
+            importLoginInfoDlg.Parent = MainWindow;
+            importLoginInfoDlg.DefaultPosition = DefWindowPosition.CenterParent;
+            importLoginInfoDlg.Run();
+        }
 		#endregion
 
 		#region Instance Menu
@@ -512,7 +531,10 @@ void ViewInstFolderClicked(object sender, InstActionEventArgs e)
 			Process.Start(SelectedInst.RootDir);
 		}
 
-		void DeleteInstClicked(object sender, InstActionEventArgs e)
+
+
+
+        void DeleteInstClicked(object sender, InstActionEventArgs e)
 		{
 			IDialog deleteDialog = GUIManager.Main.DeleteDialog();
 			deleteDialog.ShowInTaskbar = false;
@@ -1093,12 +1115,12 @@ private void ReadUserInfo(out string username, out string password)
 		{
 			try
 			{
-				if (!File.Exists(Properties.Resources.LastLoginFileName))
-				{
-					username = password = "";
-					return;
-				}
 
+                if (!File.Exists(Path.Combine(SelectedInst.RootDir, Properties.Resources.LastLoginFileName)))
+                {
+                    username = password = "";
+                    return;
+                }
 				using (SHA384 sha = SHA384.Create())
 				{
 					byte[] hash = sha.ComputeHash(
@@ -1117,7 +1139,7 @@ private void ReadUserInfo(out string username, out string password)
 
 						ICryptoTransform decryptor = rijAlg.CreateDecryptor(key, IV);
 
-						using (FileStream fsDecrypt = File.OpenRead(Properties.Resources.LastLoginFileName))
+                        using (FileStream fsDecrypt = File.OpenRead(Path.Combine(SelectedInst.RootDir, Properties.Resources.LastLoginFileName)))
 						{
 							CryptoStream csDecrypt =
 								new CryptoStream(fsDecrypt, decryptor, CryptoStreamMode.Read);
@@ -1173,7 +1195,9 @@ private void WriteUserInfo(string username, string password)
 
 					try
 					{
-						using (FileStream fsEncrypt = File.Open(Properties.Resources.LastLoginFileName,
+
+
+                        using (FileStream fsEncrypt = File.Open(Path.Combine(SelectedInst.RootDir, Properties.Resources.LastLoginFileName),
 																FileMode.Create))
 						{
 							using (CryptoStream csEncrypt =

MultiMC/MultiMC.csproj

@@ -11,6 +11,7 @@
     <RootNamespace>MultiMC</RootNamespace>
     <AssemblyName>MultiMC</AssemblyName>
     <FileAlignment>512</FileAlignment>
+    <IsWebBootstrapper>false</IsWebBootstrapper>
     <PublishUrl>publish\</PublishUrl>
     <Install>true</Install>
     <InstallFrom>Disk</InstallFrom>
@@ -23,7 +24,6 @@
     <MapFileExtensions>true</MapFileExtensions>
     <ApplicationRevision>0</ApplicationRevision>
     <ApplicationVersion>1.0.0.%2a</ApplicationVersion>
-    <IsWebBootstrapper>false</IsWebBootstrapper>
     <UseApplicationTrust>false</UseApplicationTrust>
     <BootstrapperEnabled>true</BootstrapperEnabled>
   </PropertyGroup>
@@ -147,6 +147,7 @@
     <Compile Include="GUI\IGUIManager.cs" />
     <Compile Include="GUI\IImageList.cs" />
     <Compile Include="GUI\ILoginDialog.cs" />
+    <Compile Include="GUI\IImportLoginInfoDialog.cs" />
     <Compile Include="GUI\INotesDialog.cs" />
     <Compile Include="GUI\IRestoreBackupDialog.cs" />
     <Compile Include="GUI\ISaveManagerDialog.cs" />
@@ -179,6 +180,7 @@
     <Compile Include="ConfigFile.cs" />
     <Compile Include="Tasks\Downloader.cs" />
     <Compile Include="Tasks\DirCopyTask.cs" />
+    <Compile Include="Tasks\LoginCopyTask.cs" />
     <Compile Include="Tasks\Modder.cs" />
     <Compile Include="Tasks\RestoreTask.cs" />
     <Compile Include="Tasks\SimpleTask.cs" />
@@ -208,6 +210,12 @@
     <Compile Include="WinGUI\ConsoleForm.Designer.cs">
       <DependentUpon>ConsoleForm.cs</DependentUpon>
     </Compile>
+    <Compile Include="WinGUI\ImportLoginInfoForm.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="WinGUI\ImportLoginInfoForm.Designer.cs">
+      <DependentUpon>ImportLoginInfoForm.cs</DependentUpon>
+    </Compile>
     <Compile Include="WinGUI\TextInputDialog.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -320,6 +328,9 @@
     <EmbeddedResource Include="WinGUI\ConsoleForm.resx">
       <DependentUpon>ConsoleForm.cs</DependentUpon>
     </EmbeddedResource>
+    <EmbeddedResource Include="WinGUI\ImportLoginInfoForm.resx">
+      <DependentUpon>ImportLoginInfoForm.cs</DependentUpon>
+    </EmbeddedResource>
     <EmbeddedResource Include="WinGUI\TextInputDialog.resx">
       <DependentUpon>TextInputDialog.cs</DependentUpon>
     </EmbeddedResource>
@@ -443,6 +454,7 @@
     <Content Include="WinGUI\ToolbarIcons\AboutIcon.png" />
     <Content Include="WinGUI\ToolbarIcons\CheckUpdateIcon.png" />
     <Content Include="WinGUI\ToolbarIcons\HelpIcon.png" />
+    <None Include="WinGUI\ToolbarIcons\importexporticon.png" />
     <Content Include="WinGUI\ToolbarIcons\NewInstIcon.png" />
     <Content Include="WinGUI\ToolbarIcons\RefreshInstIcon.png" />
     <Content Include="WinGUI\ToolbarIcons\RenameIcon.png" />
@@ -452,10 +464,10 @@
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>
-    <PreBuildEvent>"C:\Program Files\Java\jdk1.6.0_27\bin\javac" -d $(ProjectDir)Launcher $(ProjectDir)Launcher\MultiMCLauncher.java</PreBuildEvent>
+    <PreBuildEvent>"C:\Program Files\Java\jdk1.6.0_24\bin\javac" -d $(ProjectDir)Launcher $(ProjectDir)Launcher\MultiMCLauncher.java</PreBuildEvent>
   </PropertyGroup>
   <PropertyGroup>
-    <PostBuildEvent>copy $(TargetPath) C:\Users\Andrew\Dropbox\Public\MultiMC.exe</PostBuildEvent>
+    <PostBuildEvent>copy $(TargetPath) C:\visualstudio10\MultiMC.exe</PostBuildEvent>
   </PropertyGroup>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

MultiMC/Properties/Resources.resx

@@ -262,4 +262,7 @@
   <data name="enderman" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\resources\enderman.png;System.Drawing.Bitmap, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>
+  <data name="importexporticon" type="System.Resources.ResXFileRef, System.Windows.Forms">
+    <value>..\WinGUI\ToolbarIcons\importexporticon.png;System.Drawing.Bitmap, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
+  </data>
 </root>