diff --git a/UnitTests/ExplorerBrowser/ExplorerBrowserDemo.csproj b/UnitTests/ExplorerBrowser/ExplorerBrowserDemo.csproj
index 283c2f1f..2badde10 100644
--- a/UnitTests/ExplorerBrowser/ExplorerBrowserDemo.csproj
+++ b/UnitTests/ExplorerBrowser/ExplorerBrowserDemo.csproj
@@ -9,7 +9,7 @@
     <OutputType>WinExe</OutputType>
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <AssemblyName>ExplorerBrowser</AssemblyName>
-    <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.7.2</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <FileUpgradeFlags>
     </FileUpgradeFlags>
@@ -129,6 +129,9 @@
       <Name>Vanara.Windows.Shell</Name>
     </ProjectReference>
   </ItemGroup>
+  <ItemGroup>
+    <None Include="app.config" />
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- 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.
diff --git a/UnitTests/ExplorerBrowser/Program.cs b/UnitTests/ExplorerBrowser/Program.cs
index a57c6183..716cab50 100644
--- a/UnitTests/ExplorerBrowser/Program.cs
+++ b/UnitTests/ExplorerBrowser/Program.cs
@@ -16,7 +16,7 @@ namespace Microsoft.WindowsAPICodePack.Samples
         {
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
-            Application.Run(new ShellNamespaceTreeControlTestForm()); // ExplorerBrowserTestForm());
+            Application.Run(new ExplorerBrowserTestForm()); //ShellNamespaceTreeControlTestForm());
         }
     }
 }
\ No newline at end of file
diff --git a/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.Designer.cs b/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.Designer.cs
index 9f3a90a4..5b7aec11 100644
--- a/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.Designer.cs
+++ b/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.Designer.cs
@@ -20,22 +20,7 @@
 			base.Dispose(disposing);
 		}
 
-		#region Windows Form Designer generated code
-
-		/// <summary>
-		/// Required method for Designer support - do not modify
-		/// the contents of this method with the code editor.
-		/// </summary>
-		private void InitializeComponent()
-		{
-			this.shellNamespaceTreeControl1 = new Vanara.Windows.Forms.ShellNamespaceTreeControl();
-			this.propertyGrid1 = new System.Windows.Forms.PropertyGrid();
-			this.splitter1 = new System.Windows.Forms.Splitter();
-			this.panel1 = new System.Windows.Forms.Panel();
-			this.splitter2 = new System.Windows.Forms.Splitter();
-			this.log = new System.Windows.Forms.TextBox();
-			this.panel1.SuspendLayout();
-			this.SuspendLayout();
+		/*
 			// 
 			// shellNamespaceTreeControl1
 			// 
@@ -53,6 +38,22 @@
 			this.shellNamespaceTreeControl1.ItemMouseClick += new System.EventHandler<Vanara.Windows.Forms.ShellNamespaceTreeControlItemMouseClickEventArgs>(this.shellNamespaceTreeControl1_ItemMouseClick);
 			this.shellNamespaceTreeControl1.ItemMouseDoubleClick += new System.EventHandler<Vanara.Windows.Forms.ShellNamespaceTreeControlItemMouseClickEventArgs>(this.shellNamespaceTreeControl1_ItemMouseDoubleClick);
 			this.shellNamespaceTreeControl1.AfterSelect += new System.EventHandler(this.shellNamespaceTreeControl1_SelectionChanged);
+		*/
+		#region Windows Form Designer generated code
+
+		/// <summary>
+		/// Required method for Designer support - do not modify
+		/// the contents of this method with the code editor.
+		/// </summary>
+		private void InitializeComponent()
+		{
+			this.propertyGrid1 = new System.Windows.Forms.PropertyGrid();
+			this.splitter1 = new System.Windows.Forms.Splitter();
+			this.panel1 = new System.Windows.Forms.Panel();
+			this.splitter2 = new System.Windows.Forms.Splitter();
+			this.log = new System.Windows.Forms.TextBox();
+			this.panel1.SuspendLayout();
+			this.SuspendLayout();
 			// 
 			// propertyGrid1
 			// 
@@ -105,7 +106,6 @@
 			this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
 			this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
 			this.ClientSize = new System.Drawing.Size(729, 450);
-			this.Controls.Add(this.shellNamespaceTreeControl1);
 			this.Controls.Add(this.splitter1);
 			this.Controls.Add(this.panel1);
 			this.Name = "ShellNamespaceTreeControlTestForm";
@@ -119,7 +119,6 @@
 
 		#endregion
 
-		private Vanara.Windows.Forms.ShellNamespaceTreeControl shellNamespaceTreeControl1;
 		private System.Windows.Forms.PropertyGrid propertyGrid1;
 		private System.Windows.Forms.Splitter splitter1;
 		private System.Windows.Forms.Panel panel1;
diff --git a/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.cs b/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.cs
index 98df10c2..82efa15f 100644
--- a/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.cs
+++ b/UnitTests/ExplorerBrowser/ShellNamespaceTreeControlTestForm.cs
@@ -22,14 +22,14 @@ namespace ExplorerBrowser
 		private void ShellNamespaceTreeControlTestForm_Load(object sender, EventArgs e)
 		{
 			using var qaPidl = new PIDL("shell:::{679f85cb-0220-4080-b29b-5540cc05aab6}");
-			shellNamespaceTreeControl1.RootItems.Add(new ShellFolder(qaPidl), false, true);
-			shellNamespaceTreeControl1.RootItems.Add(ShellFolder.Desktop, true, true);
-			propertyGrid1.SelectedObject = shellNamespaceTreeControl1;
+			//shellNamespaceTreeControl1.RootItems.Add(new ShellFolder(qaPidl), false, true);
+			//shellNamespaceTreeControl1.RootItems.Add(ShellFolder.Desktop, true, true);
+			//propertyGrid1.SelectedObject = shellNamespaceTreeControl1;
 		}
 
 		private void shellNamespaceTreeControl1_SelectionChanged(object sender, EventArgs e)
 		{
-			log.AppendText("Selected item: " + shellNamespaceTreeControl1.SelectedItem?.Name ?? "[null]" + Environment.NewLine);
+			//log.AppendText("Selected item: " + shellNamespaceTreeControl1.SelectedItem?.Name ?? "[null]" + Environment.NewLine);
 		}
 
 		private void shellNamespaceTreeControl1_AfterExpand(object sender, Vanara.Windows.Forms.ShellNamespaceTreeControlEventArgs e)
diff --git a/UnitTests/ExplorerBrowser/app.config b/UnitTests/ExplorerBrowser/app.config
new file mode 100644
index 00000000..312bb3f2
--- /dev/null
+++ b/UnitTests/ExplorerBrowser/app.config
@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+<startup><supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2"/></startup></configuration>
diff --git a/UnitTests/PInvoke/DbgHelp/DbgHelpTests.cs b/UnitTests/PInvoke/DbgHelp/DbgHelpTests.cs
index 003187ee..104dc416 100644
--- a/UnitTests/PInvoke/DbgHelp/DbgHelpTests.cs
+++ b/UnitTests/PInvoke/DbgHelp/DbgHelpTests.cs
@@ -17,7 +17,7 @@ namespace Vanara.PInvoke.Tests
 	{
 		const string imgName = "imagehlp.dll";
 		const string testAppName = "TestDbgApp";
-		const string testAppPath = TestCaseSources.TempDirWhack + testAppName + ".exe";
+		static readonly string testAppPath = TestCaseSources.TempDirWhack + testAppName + ".exe";
 		private Process testApp;
 		private ProcessSymbolHandler hProc;
 
diff --git a/UnitTests/PInvoke/Kernel32/FileApiTests.cs b/UnitTests/PInvoke/Kernel32/FileApiTests.cs
index 1cd811ee..caceb082 100644
--- a/UnitTests/PInvoke/Kernel32/FileApiTests.cs
+++ b/UnitTests/PInvoke/Kernel32/FileApiTests.cs
@@ -56,7 +56,7 @@ namespace Vanara.PInvoke.Tests
 		[Test]
 		public void CreateDirectoryTest()
 		{
-			const string dir = TestCaseSources.TempChildDir;
+			string dir = TestCaseSources.TempChildDir;
 			Assert.That(CreateDirectory(dir), Is.True);
 			Assert.That(System.IO.Directory.Exists(dir), Is.True);
 			Assert.That(RemoveDirectory(dir), Is.True);
@@ -113,7 +113,7 @@ namespace Vanara.PInvoke.Tests
 		public void DefineDosDeviceTest()
 		{
 			const string src = "M:";
-			const string target = TestCaseSources.TempDir;
+			string target = TestCaseSources.TempDir;
 
 			var c = QueryDosDevice(src).ToArray().Length;
 			Assert.That(DefineDosDevice(DDD.DDD_NO_BROADCAST_SYSTEM, src, target), Is.True);
@@ -176,7 +176,7 @@ namespace Vanara.PInvoke.Tests
 
 			void FileMaker()
 			{
-				const string fn = TestCaseSources.TempDir + @"\_tempFile.txt";
+				string fn = TestCaseSources.TempDir + @"\_tempFile.txt";
 				while (keepGoing)
 				{
 					Thread.Sleep(200);
diff --git a/UnitTests/PInvoke/Kernel32/Kernel32Tests.cs b/UnitTests/PInvoke/Kernel32/Kernel32Tests.cs
index a4331782..df7e8169 100644
--- a/UnitTests/PInvoke/Kernel32/Kernel32Tests.cs
+++ b/UnitTests/PInvoke/Kernel32/Kernel32Tests.cs
@@ -11,7 +11,7 @@ namespace Vanara.PInvoke.Tests
 	[TestFixture]
 	public class Kernel32Tests
 	{
-		internal const string fn = TestCaseSources.SmallFile;
+		internal static readonly string fn = TestCaseSources.SmallFile;
 		internal const string tmpstr = @"Temporary";
 
 		public static string CreateTempFile(bool markAsTemp = true)
diff --git a/UnitTests/PInvoke/Kernel32/WinBase.FileTests.cs b/UnitTests/PInvoke/Kernel32/WinBase.FileTests.cs
index e5592b99..52ba1633 100644
--- a/UnitTests/PInvoke/Kernel32/WinBase.FileTests.cs
+++ b/UnitTests/PInvoke/Kernel32/WinBase.FileTests.cs
@@ -16,8 +16,8 @@ namespace Vanara.PInvoke.Tests
 	[TestFixture]
 	public partial class WinBaseTests_File
 	{
-		private const string bigfn = TestCaseSources.LargeFile;
-		private const string fn = TestCaseSources.SmallFile;
+		private static readonly string bigfn = TestCaseSources.LargeFile;
+		private static readonly string fn = TestCaseSources.SmallFile;
 		private const string newfn = @"C:\Temp\help2.ico";
 
 		[Test]
@@ -105,7 +105,7 @@ namespace Vanara.PInvoke.Tests
 		public void EnumVolumeMountPointsTest()
 		{
 			// Setup a new mount on C:
-			const string mntDir = TestCaseSources.TempDirWhack + @"Mounted\";
+			string mntDir = TestCaseSources.TempDirWhack + @"Mounted\";
 			var sb = new StringBuilder(100);
 			Assert.That(GetVolumeNameForVolumeMountPoint(@"C:\", sb, (uint)sb.Capacity), ResultIs.Successful);
 			var cvol = sb.ToString();
@@ -167,7 +167,7 @@ namespace Vanara.PInvoke.Tests
 		[Test]
 		public void MoveFileExTest()
 		{
-			const string newFld = TestCaseSources.TempChildDir;
+			string newFld = TestCaseSources.TempChildDir;
 			Assert.That(MoveFileEx(fn, Path.Combine(newFld, Path.GetFileName(fn)), MOVEFILE.MOVEFILE_REPLACE_EXISTING), ResultIs.Successful);
 			Assert.That(MoveFileEx(Path.Combine(newFld, Path.GetFileName(fn)), fn, MOVEFILE.MOVEFILE_REPLACE_EXISTING), ResultIs.Successful);
 		}
@@ -175,7 +175,7 @@ namespace Vanara.PInvoke.Tests
 		[Test]
 		public void MoveFileTest()
 		{
-			const string newFld = TestCaseSources.TempChildDir;
+			string newFld = TestCaseSources.TempChildDir;
 			Assert.That(MoveFile(fn, Path.Combine(newFld, Path.GetFileName(fn))), ResultIs.Successful);
 			Assert.That(MoveFile(Path.Combine(newFld, Path.GetFileName(fn)), fn), ResultIs.Successful);
 		}
@@ -183,7 +183,7 @@ namespace Vanara.PInvoke.Tests
 		[Test]
 		public void MoveFileWithProgressTest()
 		{
-			const string newFld = TestCaseSources.TempChildDir;
+			string newFld = TestCaseSources.TempChildDir;
 			var qtr = 0;
 			Assert.That(MoveFileWithProgress(bigfn, Path.Combine(newFld, Path.GetFileName(bigfn)), fProgress, default, MOVEFILE.MOVEFILE_REPLACE_EXISTING), ResultIs.Successful);
 			Assert.That(MoveFileWithProgress(Path.Combine(newFld, Path.GetFileName(bigfn)), bigfn, fProgress, default, MOVEFILE.MOVEFILE_REPLACE_EXISTING), ResultIs.Successful);
diff --git a/UnitTests/PInvoke/Kernel32/WinBase.ResourceTests.cs b/UnitTests/PInvoke/Kernel32/WinBase.ResourceTests.cs
index 3dc95023..5d667492 100644
--- a/UnitTests/PInvoke/Kernel32/WinBase.ResourceTests.cs
+++ b/UnitTests/PInvoke/Kernel32/WinBase.ResourceTests.cs
@@ -6,7 +6,7 @@ namespace Vanara.PInvoke.Tests
 	[TestFixture]
 	public partial class WinBaseTests_Resource
 	{
-		private const string ResExe = TestCaseSources.ResourceFile;
+		private static readonly string ResExe = TestCaseSources.ResourceFile;
 		private const int ResId1 = 103;
 		private const int ResId2 = 129;
 		private const int ResType = (int)ResourceType.RT_DIALOG;
diff --git a/UnitTests/PInvoke/Security/AdvApi32/AdvApi32Tests.cs b/UnitTests/PInvoke/Security/AdvApi32/AdvApi32Tests.cs
index 204a636c..6076298c 100644
--- a/UnitTests/PInvoke/Security/AdvApi32/AdvApi32Tests.cs
+++ b/UnitTests/PInvoke/Security/AdvApi32/AdvApi32Tests.cs
@@ -19,7 +19,7 @@ namespace Vanara.PInvoke.Tests
 	public class AdvApi32Tests
 	{
 		internal const SECURITY_INFORMATION AllSI = SECURITY_INFORMATION.OWNER_SECURITY_INFORMATION | SECURITY_INFORMATION.GROUP_SECURITY_INFORMATION | SECURITY_INFORMATION.DACL_SECURITY_INFORMATION | SECURITY_INFORMATION.SACL_SECURITY_INFORMATION;
-		internal const string fn = TestCaseSources.SmallFile;
+		internal static readonly string fn = TestCaseSources.SmallFile;
 
 		[Test()]
 		public void ConvertSecurityDescriptorToStringSecurityDescriptorTest()
diff --git a/UnitTests/PInvoke/Security/AdvApi32/EvnTraceTests.cs b/UnitTests/PInvoke/Security/AdvApi32/EvnTraceTests.cs
index bd156ddd..e4d4a67d 100644
--- a/UnitTests/PInvoke/Security/AdvApi32/EvnTraceTests.cs
+++ b/UnitTests/PInvoke/Security/AdvApi32/EvnTraceTests.cs
@@ -15,7 +15,7 @@ namespace Vanara.PInvoke.Tests
 	[TestFixture()]
 	public partial class EvnTraceTests
 	{
-		private const string logfilePath = TestCaseSources.EventFile;
+		private static readonly string logfilePath = TestCaseSources.EventFile;
 
 		[Test]
 		public void EnumerateTraceGuidsTest()
diff --git a/UnitTests/PInvoke/Security/AdvApi32/WinBase_EventLogTests.cs b/UnitTests/PInvoke/Security/AdvApi32/WinBase_EventLogTests.cs
index a59c932e..361374ca 100644
--- a/UnitTests/PInvoke/Security/AdvApi32/WinBase_EventLogTests.cs
+++ b/UnitTests/PInvoke/Security/AdvApi32/WinBase_EventLogTests.cs
@@ -11,7 +11,7 @@ namespace Vanara.PInvoke.Tests
 	[TestFixture()]
 	public class WinBase_EventLogTests
 	{
-		private const string eventLogName = TestCaseSources.LogFile;
+		private static readonly string eventLogName = TestCaseSources.LogFile;
 
 		[Test]
 		public void OpenBackupClearCloseEventLogTest()
diff --git a/UnitTests/PInvoke/Shell32/IconTests.cs b/UnitTests/PInvoke/Shell32/IconTests.cs
index ed83a5b0..bda3ddb0 100644
--- a/UnitTests/PInvoke/Shell32/IconTests.cs
+++ b/UnitTests/PInvoke/Shell32/IconTests.cs
@@ -15,7 +15,7 @@ namespace Vanara.PInvoke.Tests
 		[Test]
 		public void ExtractAssociatedIconTest()
 		{
-			const string icoFile = TestCaseSources.WordDoc;
+			string icoFile = TestCaseSources.WordDoc;
 			var sb = new StringBuilder(icoFile, MAX_PATH);
 			ushort iidx = 0;
 			using (var hIcon = ExtractAssociatedIcon(HINSTANCE.NULL, sb, ref iidx))
@@ -26,7 +26,7 @@ namespace Vanara.PInvoke.Tests
 		[Test]
 		public void ExtractAssociatedIconExTest()
 		{
-			const string icoFile = TestCaseSources.WordDoc;
+			string icoFile = TestCaseSources.WordDoc;
 			var sb = new StringBuilder(icoFile, MAX_PATH);
 			ushort iidx = 0, iid = 0;
 			using (var hIcon = ExtractAssociatedIconEx(HINSTANCE.NULL, sb, ref iidx, ref iid))
diff --git a/UnitTests/VirtualDisk/VirtualDiskTests.cs b/UnitTests/VirtualDisk/VirtualDiskTests.cs
index 213dd8b5..c5f54adc 100644
--- a/UnitTests/VirtualDisk/VirtualDiskTests.cs
+++ b/UnitTests/VirtualDisk/VirtualDiskTests.cs
@@ -12,9 +12,9 @@ namespace Vanara.IO.Tests
 	[TestFixture()]
 	public class VirtualDiskTests
 	{
-		const string tmpfn = Vanara.PInvoke.Tests.TestCaseSources.TempDirWhack + "TestVHD.vhd";
-		const string tmpcfn = Vanara.PInvoke.Tests.TestCaseSources.TempDirWhack + "TestVHD - Diff.vhd";
-		const string fn = Vanara.PInvoke.Tests.TestCaseSources.VirtualDisk;
+		static readonly string tmpfn = Vanara.PInvoke.Tests.TestCaseSources.TempDirWhack + "TestVHD.vhd";
+		static readonly string tmpcfn = Vanara.PInvoke.Tests.TestCaseSources.TempDirWhack + "TestVHD - Diff.vhd";
+		static readonly string fn = Vanara.PInvoke.Tests.TestCaseSources.VirtualDisk;
 
 		[Test()]
 		public void CreateDynPropTest()
diff --git a/UnitTests/Windows.Shell/ShellFolderTests.cs b/UnitTests/Windows.Shell/ShellFolderTests.cs
index 74c31b05..b3666ecd 100644
--- a/UnitTests/Windows.Shell/ShellFolderTests.cs
+++ b/UnitTests/Windows.Shell/ShellFolderTests.cs
@@ -9,7 +9,7 @@ namespace Vanara.Windows.Shell.Tests
 	[TestFixture, SingleThreaded]
 	public class ShellFolderTests
 	{
-		private const string testFile = ShellItemTests.testDoc;
+		private static readonly string testFile = ShellItemTests.testDoc;
 		private static readonly string testFld = Path.GetDirectoryName(testFile);
 
 		[Test]
diff --git a/UnitTests/Windows.Shell/ShellItemPropStoreTests.cs b/UnitTests/Windows.Shell/ShellItemPropStoreTests.cs
index ada50ddd..c50da3c7 100644
--- a/UnitTests/Windows.Shell/ShellItemPropStoreTests.cs
+++ b/UnitTests/Windows.Shell/ShellItemPropStoreTests.cs
@@ -12,7 +12,7 @@ namespace Vanara.Windows.Shell.Tests
 	[TestFixture]
 	public class ShellItemPropStoreTests
 	{
-		private const string testDoc = ShellItemTests.testDoc;
+		private static readonly string testDoc = ShellItemTests.testDoc;
 
 		[Test]
 		public void DescriptionTest()
diff --git a/UnitTests/Windows.Shell/ShellItemTests.cs b/UnitTests/Windows.Shell/ShellItemTests.cs
index 2e7a3988..003f79aa 100644
--- a/UnitTests/Windows.Shell/ShellItemTests.cs
+++ b/UnitTests/Windows.Shell/ShellItemTests.cs
@@ -13,8 +13,8 @@ namespace Vanara.Windows.Shell.Tests
 	public class ShellItemTests
 	{
 		internal const string badTestDoc = @"C:\Temp\BadTest.doc";
-		internal const string testDoc = PInvoke.Tests.TestCaseSources.WordDoc;
-		internal const string testLinkDoc = PInvoke.Tests.TestCaseSources.WordDocLink;
+		internal static readonly string testDoc = PInvoke.Tests.TestCaseSources.WordDoc;
+		internal static readonly string testLinkDoc = PInvoke.Tests.TestCaseSources.WordDocLink;
 
 		[Test]
 		public void EqualityTest()