Perhaps I should have asked this question before I started down the multi server path. My VPS has 2 Gigs memory ( I think ). It's only running about 10 low traffic websites right now. I created a domain: WhiteOakBooks.com in WhiteOakBooks.com/forums I installed IPBoard. I had no problems the 1st night... created and set it up just fine. Since then I get to the main forum page fine but I get 500 errors trying to sign into the forums. Is this a PHP memory problem? I did not see the option to allocate more memory to PHP in the domain settings. Invision won't provide technical support if their software is install on an IIS machine. Both the domain and forum are expected to be low volume. Should IIS be able to handle this?