求助，载入游戏时跳出！！！

ccxq

我的电脑显卡是7300的显卡，装的时候也已经装了XNA和NET3.5。游戏可以正常进入，但是创建人物后点开始一载入完游戏就跳出，错误报告如下，希望有朋友能帮忙解决下，谢谢啦~
Version: 1.3.4.0
Thread: LoaderThread
Microsoft.Xna.Framework.Graphics.OutOfVideoMemoryException: External component has thrown an exception.
   at Microsoft.Xna.Framework.Graphics.RenderTarget.CreateRenderTarget(GraphicsDevice graphicsDevice, Int32 width, Int32 height, Int32 numberLevels, SurfaceFormat format, MultiSampleType multiSampleType, Int32 multiSampleQuality, RenderTargetUsage usage, Boolean isTexture2D, _D3DSURFACE_DESC* pDesc)
   at Microsoft.Xna.Framework.Graphics.RenderTarget..ctor(GraphicsDevice graphicsDevice, Int32 width, Int32 height, Int32 numberLevels, SurfaceFormat format, MultiSampleType multiSampleType, Int32 multiSampleQuality, RenderTargetUsage usage, Boolean isTexture2D)
   at Microsoft.Xna.Framework.Graphics.RenderTarget2D..ctor(GraphicsDevice graphicsDevice, Int32 width, Int32 height, Int32 numberLevels, SurfaceFormat format, MultiSampleType multiSampleType, Int32 multiSampleQuality, RenderTargetUsage usage)
   at PolygonHead.Lights.DirectionalLight.CreateShadowMap()
   at PolygonHead.Lights.DirectionalLight.set_CastShadows(Boolean value)
   at Magicka.Levels.LevelModel..ctor(ContentReader iInput)
   at Magicka.ContentReaders.LevelModelReader.Read(ContentReader input, LevelModel existingInstance)
   at Microsoft.Xna.Framework.Content.ContentReader.InvokeReader[T](ContentTypeReader reader, Object existingInstance)
   at Microsoft.Xna.Framework.Content.ContentReader.ReadObjectInternal[T](Object existingInstance)
   at Microsoft.Xna.Framework.Content.ContentReader.ReadObject[T]()
   at Microsoft.Xna.Framework.Content.ContentReader.ReadAsset[T]()
   at Microsoft.Xna.Framework.Content.ContentManager.ReadAsset[T](String assetName, Action`1 recordDisposableObject)
   at Magicka.SharedContentManager.CommonContentManager.Load[T](String assetName)
   at Magicka.SharedContentManager.Load[T](String assetName)
   at Magicka.Levels.GameScene.Initialize(SpawnPoint iSpawnPoint, Boolean iClearAudio)
   at Magicka.Levels.Level.ChangeScene()
   at Magicka.Levels.Level.GoToScene(SpawnPoint iSpawnPoint, Transitions iTransition, Single iTransitionTime, Boolean iSaveNPCs)
   at Magicka.GameLogic.GameStates.PlayState.Initialize()
   at Magicka.Game.LoaderFunction()