Permission Error + File Uploader

I am using the Ajax File Uploader, the site (ASP.net WebForms) is running as network service and it has permissions to the stated folder but it still causes an error

System.UnauthorizedAccessException: Access to the path 'C:\Windows\TEMP\_AjaxFileUpload' is denied.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.Directory.InternalCreateDirectory(String fullPath, String path, Object dirSecurityObj, Boolean checkHost)
   at System.IO.Directory.InternalCreateDirectoryHelper(String path, Boolean checkHost)
   at AjaxControlToolkit.AjaxFileUpload.BuildRootTempFolder()
   at AjaxControlToolkit.AjaxFileUpload.UploadRequestProcessor.XhrDone(String fileId)
   at AjaxControlToolkit.AjaxFileUpload.UploadRequestProcessor.ProcessRequest()
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.AddedControl(Control control, Int32 index)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Control.InitRecursive(Control namingContainer)
   at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

<act:AjaxFileUpload ID="actFileUplad" MaximumNumberOfFiles="1" CssClass="paddingleft1 margintop15" Width="343px" OnUploadComplete="OnUploadComplete" runat="server" Mode="Auto" />