为什么我的Visual Studio 2008停止识别.aspx和.css文件？

I formatted and reinstalled my system today. I reinstalled VS 2008, but all my .aspx pages are no longer syntax highlighted (the text editor displays them in plain black font color) and IntelliSense isn't working on these pages either. The font color issue appears for .css files, too.I formatted and reinstalled my system today. I