I recently upgraded to .net 3.5 SP1 and since then it takes about 20 seconds for WLW to open a new window. Very annoying. Used to do so immediately. I tried switching the default browser and it doesn't matter what browser I use. Same behavior. View Site, Dashboard, Help|Community Forums... etc.. no matter what link in WLW I press there is a long pause in which WLW freezes up and says not responding.
I would try reinstalling .net 3.5sp1, that is what we have been developing and testing against for a few months and havent seen any problems. What OS are you on?-Brandon Turner [MSFT]