Please try the following code and set a different temporary directory, please grant "everyone" full permission:
<html xmlns="
http://www.w3.org/1999/xhtml">
<head id="Head2" runat="server"></head>
<body>
<form id="form2" runat="server">
<CuteWebUI:Uploader id="Uploader1" TempDirectory="~/tempdir" runat="server"></CuteWebUI:Uploader>
</form>
</body>
</html>
Does it work fine?
Regards,
Eric