diff --git a/Ninjacrab.PersistentWindows.Solution/Common/PersistentWindowProcessor.cs b/Ninjacrab.PersistentWindows.Solution/Common/PersistentWindowProcessor.cs
index e42dc67..c2b05c0 100644
--- a/Ninjacrab.PersistentWindows.Solution/Common/PersistentWindowProcessor.cs
+++ b/Ninjacrab.PersistentWindows.Solution/Common/PersistentWindowProcessor.cs
@@ -34,7 +34,7 @@ namespace PersistentWindows.Common
         private const int UserMoveLatency = 1000; // delay in milliseconds from user move/minimize/unminimize/maximize to capture, must < CaptureLatency
         private const int MaxUserMoves = 4; // max user window moves per capture cycle
         private const int MinWindowOsMoveEvents = 12; // threshold of window move events initiated by OS per capture cycle
-        private const int MaxSnapshots = 37; // 0-9, a-z, and final one for undo
+        private const int MaxSnapshots = 38; // 0-9, a-z, ` and final one for undo
         private const int MaxHistoryQueueLength = 40; // must be bigger than MaxSnapshots + 1
 
         private const int PauseRestoreTaskbar = 3500; //cursor idle time before dragging taskbar
@@ -510,6 +510,13 @@ namespace PersistentWindows.Common
                     Log.Event("Restore finished in pass {0} with {1} windows recovered for display setting {2}", restorePass, numWindowRestored, curDisplayKey);
                     sessionActive = true;
 
+                    if (!wasRestoringSnapshot)
+                    {
+                        if (!snapshotTakenTime.ContainsKey(curDisplayKey))
+                            snapshotTakenTime[curDisplayKey] = new Dictionary<int, DateTime>();
+                        snapshotTakenTime[curDisplayKey][MaxSnapshots - 2] = lastUserActionTime[curDisplayKey];
+                    }
+
                     if (wasRestoringSnapshot || noRestoreWindowsTmp.Count > 0)
                         CaptureApplicationsOnCurrentDisplays(curDisplayKey, immediateCapture: true);
                     else
diff --git a/Ninjacrab.PersistentWindows.Solution/SystrayShell/Program.cs b/Ninjacrab.PersistentWindows.Solution/SystrayShell/Program.cs
index f17ec94..635825f 100644
--- a/Ninjacrab.PersistentWindows.Solution/SystrayShell/Program.cs
+++ b/Ninjacrab.PersistentWindows.Solution/SystrayShell/Program.cs
@@ -25,6 +25,8 @@ namespace PersistentWindows.SystrayShell
         public static bool Gui = true;
         public static bool hotkey_window = true;
 
+        private const int MaxSnapshots = 38; // 0-9, a-z, ` and final one for undo
+
         static PersistentWindowProcessor pwp = null;    
         static SystrayForm systrayForm = null;
         static bool silent = false; //suppress all balloon tip & sound prompt
@@ -514,6 +516,8 @@ namespace PersistentWindows.SystrayShell
                 c = '0';
                 c += (char)id;
             }
+            else if (id == MaxSnapshots - 2)
+                c = '`';
             else
             {
                 c = 'a';
@@ -525,6 +529,8 @@ namespace PersistentWindows.SystrayShell
 
         static public int SnapshotCharToId(char c)
         {
+            if (c == '`')
+                return MaxSnapshots - 2;
             if (c < '0')
                 return -1;
             if (c > 'z')
diff --git a/Ninjacrab.PersistentWindows.Solution/SystrayShell/SystrayForm.cs b/Ninjacrab.PersistentWindows.Solution/SystrayShell/SystrayForm.cs
index a1d3c2d..bdb1c73 100644
--- a/Ninjacrab.PersistentWindows.Solution/SystrayShell/SystrayForm.cs
+++ b/Ninjacrab.PersistentWindows.Solution/SystrayShell/SystrayForm.cs
@@ -15,6 +15,8 @@ namespace PersistentWindows.SystrayShell
 {
     public partial class SystrayForm : Form
     {
+        private const int MaxSnapshots = 38; // 0-9, a-z, ` and final one for undo
+
         public bool restoreToolStripMenuItemEnabled;
         public bool restoreSnapshotMenuItemEnabled;
 
@@ -70,11 +72,11 @@ namespace PersistentWindows.SystrayShell
 
             pauseUpgradeCounter = true;
 
-            int keyPressed = -1;
+            Keys keyPressed = Keys.None;
             //check 0-9 key pressed
-            for (int i = 0x30; i < 0x3a; ++i)
+            for (Keys i = Keys.D0; i <= Keys.D9; ++i)
             {
-                if (User32.GetAsyncKeyState(i) != 0)
+                if (User32.GetAsyncKeyState((int)i) != 0)
                 {
                     keyPressed = i;
                     break;
@@ -82,16 +84,24 @@ namespace PersistentWindows.SystrayShell
             }
 
             //check a-z pressed
-            if (keyPressed < 0)
-            for (int i = 0x41; i < 0x5b; ++i)
+            if (keyPressed == Keys.None)
+            for (Keys i = Keys.A; i <= Keys.Z; ++i)
             {
-                if (User32.GetAsyncKeyState(i) != 0)
+                if (User32.GetAsyncKeyState((int)i) != 0)
                 {
                     keyPressed = i;
                     break;
                 }
             }
 
+            if (keyPressed == Keys.None)
+            {
+                if (User32.GetAsyncKeyState((int)Keys.Oem3) != 0)
+                {
+                    keyPressed = Keys.Oem3;
+                }
+            }
+
             int totalSpecialKeyPressed = shiftKeyPressed + altKeyPressed;
 
             if (clickCount > 2)
@@ -104,7 +114,7 @@ namespace PersistentWindows.SystrayShell
             else if (altKeyPressed == clickCount && altKeyPressed != 0 && ctrlKeyPressed == 0)
             {
                 //restore previous workspace (not necessarily a snapshot)
-                Program.RestoreSnapshot(36); //MaxSnapShot - 1
+                Program.RestoreSnapshot(MaxSnapshots - 1);
             }
             else
             {
@@ -128,12 +138,14 @@ namespace PersistentWindows.SystrayShell
                 else
                 {
                     int snapshot;
-                    if (keyPressed < 0x3a)
-                        snapshot = keyPressed - 0x30;
+                    if (keyPressed == Keys.Oem3)
+                        snapshot = MaxSnapshots - 2;
+                    else if (keyPressed <= Keys.D9)
+                        snapshot = keyPressed - Keys.D0;
                     else
-                        snapshot = keyPressed - 0x41 + 10; 
+                        snapshot = keyPressed - Keys.A + 10; 
 
-                    if (snapshot < 0 || snapshot > 35)
+                    if (snapshot < 0 || snapshot > MaxSnapshots - 2)
                     {
                         //invalid key pressed
                     }
@@ -407,15 +419,17 @@ namespace PersistentWindows.SystrayShell
                 Console.WriteLine("MouseClick");
 
                 // clear memory of keyboard input
-                for (int i = 0x30; i < 0x3a; ++i)
+                for (Keys i = Keys.D0; i <= Keys.D9; ++i)
                 {
-                    User32.GetAsyncKeyState(i);
+                    User32.GetAsyncKeyState((int)i);
                 }
 
-                for (int i = 0x41; i < 0x5b; ++i)
+                for (Keys i = Keys.A; i <= Keys.Z; ++i)
                 {
-                    User32.GetAsyncKeyState(i);
+                    User32.GetAsyncKeyState((int)i);
                 }
+
+                User32.GetAsyncKeyState((int)Keys.Oem3);
             }
         }