diff --git a/trunk/ProcessHacker.Native/Api/Functions.cs b/trunk/ProcessHacker.Native/Api/Functions.cs
index cc20a37c3..bf1809da9 100644
--- a/trunk/ProcessHacker.Native/Api/Functions.cs
+++ b/trunk/ProcessHacker.Native/Api/Functions.cs
@@ -2332,7 +2332,7 @@ namespace ProcessHacker.Native.Api
             );
 
         [DllImport("uxtheme.dll", CharSet = CharSet.Unicode)]
-        public static extern int SetWindowTheme(
+        public static extern HResult SetWindowTheme(
             [In] IntPtr hWnd,
             [In] string appName,
             [In] string idList
diff --git a/trunk/ProcessHacker/Common/PhUtils.cs b/trunk/ProcessHacker/Common/PhUtils.cs
index eb1a52bc8..0028216d2 100644
--- a/trunk/ProcessHacker/Common/PhUtils.cs
+++ b/trunk/ProcessHacker/Common/PhUtils.cs
@@ -314,7 +314,8 @@ namespace ProcessHacker.Common
         /// <param name="theme">A name of a theme.</param>
         public static void SetTheme(this Control control, string theme)
         {
-            Win32.SetWindowTheme(control.Handle, theme, null);
+           HResult setWindowThemeResult = Win32.SetWindowTheme(control.Handle, theme, null);
+           setWindowThemeResult.ThrowIf();
         }
 
         /// <summary>
diff --git a/trunk/ProcessHacker/Components/ExtendedListView.cs b/trunk/ProcessHacker/Components/ExtendedListView.cs
index f5d09424e..629df414f 100644
--- a/trunk/ProcessHacker/Components/ExtendedListView.cs
+++ b/trunk/ProcessHacker/Components/ExtendedListView.cs
@@ -163,7 +163,9 @@ namespace ProcessHacker
             {
                 case 0x1: /*WM_CREATE*/
                     {
-                        Win32.SetWindowTheme(this.Handle, "explorer", null);
+                        HResult setThemeResult = Win32.SetWindowTheme(this.Handle, "explorer", null);
+                        setThemeResult.ThrowIf();
+                        
                         Win32.SendMessage(this.Handle, (WindowMessage)LVM_SetExtendedListViewStyle, LVS_Ex_DoubleBuffer, LVS_Ex_DoubleBuffer);
                         break;
                     }                  
diff --git a/trunk/ProcessHacker/Components/ExtendedTreeView.cs b/trunk/ProcessHacker/Components/ExtendedTreeView.cs
index 70c84107e..53a9d11b2 100644
--- a/trunk/ProcessHacker/Components/ExtendedTreeView.cs
+++ b/trunk/ProcessHacker/Components/ExtendedTreeView.cs
@@ -41,7 +41,8 @@ public class VistaTreeView : System.Windows.Forms.TreeView
         if (OSVersion.IsAboveOrEqual(WindowsVersion.Vista))
         {
             Win32.SendMessage(this.Handle, (WindowMessage)TVM_SETEXTENDEDSTYLE, 0, TVS_EX_FADEINOUTEXPANDOS);
-            Win32.SetWindowTheme(this.Handle, "explorer", null);
+            HResult setThemeResult = Win32.SetWindowTheme(this.Handle, "explorer", null);
+            setThemeResult.ThrowIf();
         }
         base.OnHandleCreated(e);
     }
diff --git a/trunk/ProcessHacker/Components/TaskbarLib/Interop/Interop.cs b/trunk/ProcessHacker/Components/TaskbarLib/Interop/Interop.cs
index c5b237755..dee0a96e6 100644
--- a/trunk/ProcessHacker/Components/TaskbarLib/Interop/Interop.cs
+++ b/trunk/ProcessHacker/Components/TaskbarLib/Interop/Interop.cs
@@ -174,7 +174,7 @@ namespace TaskbarLib.Interop
         private CALPWSTR calpwstr;
 
         [DllImport("ole32.dll")]
-        private static extern int PropVariantClear(ref PropVariant pvar);
+        private static extern HResult PropVariantClear(ref PropVariant pvar);
 
         public VarEnum VarType
         {
@@ -202,7 +202,8 @@ namespace TaskbarLib.Interop
 
         public void Clear()
         {
-            PropVariantClear(ref this);
+           HResult clearResult = PropVariantClear(ref this);
+           clearResult.ThrowIf();
         }
 
         public void Dispose()