If you're ever doing renovations, please, please do not put wall paper on unprimed drywall. It's just not kind, and primer is cheap. This wallpaper is everywhere in this house. EVERYWHERE. We knew it when we bought it, but didn't really think about the work involved in getting rid of it. To top it off, the paper is filled with little wood chips AND has been painted. We've gone through three wallpaper scorers, have used heat guns, steamers and paint scrapers to get this crap gone.
The best method we have found, when dealing with the un-primed walls underneath, is to separate the wallpaper and peel off the top layer first. Then, saturate the wall with water/vinegar in a sprayer, then scrape of gently with a wide paint scraper.
The wall scorer works very well when their is paint or primer underneath - otherwise, it doesn't do enough to saturate the glue holding the paper down onto the wall.