NetGore

Does it say anything when it crashes?

It says something like "demogame.client has encountered a problem and needs to close". In the "what does this report contain", the error signature has something like this: appname: demogame.client.exe modname:ntdll.dll

Run the client from the vs IDE? If it still crashes, tell us the line?

I debugged the client, and this came up:
System.AccessViolationException was unhandled
Message=Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Source=NetGore
StackTrace:
at SFML.Graphics.RenderImage.sfRenderImage_Destroy(IntPtr This)
at SFML.Graphics.RenderImage.Destroy(Boolean disposing) in C:\NetGore\NetGore\SFML\Graphics\NetGore\RenderImage.cs:line 149
at SFML.ObjectBase.Dispose(Boolean disposing) in C:\NetGore\NetGore\SFML\Window\NetGore\ObjectBase.cs:line 79
at SFML.ObjectBase.Dispose() in C:\NetGore\NetGore\SFML\Window\NetGore\ObjectBase.cs:line 113
at NetGore.Graphics.WindowExtensions.CreateBufferRenderImage(Window w, RenderImage ri, Boolean disposeExisting) in C:\NetGore\NetGore\Graphics\Extensions\WindowExtensions.cs:line 76
at NetGore.Graphics.DrawingManager.BeginDrawGUI(Boolean clearBuffer) in C:\NetGore\NetGore\Graphics\DrawingManager\DrawingManager.cs:line 304
at DemoGame.Client.GameMenuScreenBase.Draw(TickCount gameTime) in C:\NetGore\DemoGame.Client\Screens\GameMenuScreenBase.cs:line 89
at NetGore.Graphics.GUI.ScreenManager.Draw(TickCount gameTime) in C:\NetGore\NetGore\Graphics\GUI\Screen Manager\ScreenManager.cs:line 103
at DemoGame.Client.DemoGame.HandleDraw(TickCount currentTime) in C:\NetGore\DemoGame.Client\DemoGame.cs:line 280
at NetGore.Graphics.GameBase.HandleFrame() in C:\NetGore\NetGore\Graphics\Game Container\GameBase.cs:line 754
at DemoGame.Client.GameForm.HandleFrame() in C:\NetGore\DemoGame.Client\GameForm.cs:line 58
at DemoGame.Client.GameForm.WndProc(Message& m) in C:\NetGore\DemoGame.Client\GameForm.cs:line 136
at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
at System.Windows.Forms.Application.Run(Form mainForm)
at DemoGame.Client.DemoGame.RunCustomWindowedDisplayHandleLoop(Object displayContainer) in C:\NetGore\DemoGame.Client\DemoGame.cs:line 355
at NetGore.Graphics.GameBase.Run() in C:\NetGore\NetGore\Graphics\Game Container\GameBase.cs:line 786
at DemoGame.Client.Program.Main() in C:\NetGore\DemoGame.Client\Program.cs:line 51
at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.AppDomain.nExecuteAssembly(RuntimeAssembly assembly, String[] args)
at System.Runtime.Hosting.ManifestRunner.Run(Boolean checkAptModel)
at System.Runtime.Hosting.ManifestRunner.ExecuteAsAssembly()
at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext, String[] activationCustomData)
at System.Runtime.Hosting.ApplicationActivator.CreateInstance(ActivationContext activationContext)
at System.Activator.CreateInstance(ActivationContext activationContext)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssemblyDebugInZone()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
InnerException:

Try checking out the latest version from the SVN repository (http://code.google.com/p/netgore/source/checkout). If you haven't used SVN before, the easiest Windows-based client to use is TortoiseSVN.