All my other Dawn of Wars install fine, but for some reason Winter Assault, which does actually 'seem' to install and finish properly, after it updates DoW before installation, many Internal Error 2909 and 2908 boxes pop up with a long code under each one.

Clicking the shortcut for Winter Assault makes the game try to install itself again, and fail. I never had this problem before.

I'm on Windows XP SP3.