The Forums are back up. Please see this post from the blog to read more about the situation with the Forums.
MSPARP does not have advertisements on it, so if you are seeing ads on this page, you likely have been infected with adware. Google "remove adware" for solutions on how to remove it.
If you have trouble registering and are getting a 403 forbidden page when you try, just keep trying. It will work eventually. We're still trying to figure out why it does this.
We've added age restriction to MSPARP. Please read this tumblr post for more details.