The global default build tree(winceroot)has not been set,or is invalid,该如何解决

The global default build tree(winceroot)has not been set,or is invalid
Make sure that the WINCEBOOT is set correctly before open an OS design


用VS2005打开ARM9开发板的BSP时出现这个错误,有没有人知道是为什么啊?难道WINCE非得装在根目录?
目前是装在
D:\Program Files\WinCE6

------解决方案--------------------
是不是VS2005里面可以设置BSP的，顶顶！