Just copied my site (HTML files and Database) from a Linux (Apache) server to a Microsoft (IIS) server -- I also edited the wp_options table ("siteurl" and "home") to reflect the new domain name. Now I get the following error after logging in as admin, "You do not have sufficient permissions to access this page."
Everything else works fine (except URL rewrites): site loads, ugly URLs work fine ... even the login process itself seems to work correctly ...
But when I go to /wp-admin, I get redirected to /wp-login (as expected), then putting in valid admin credentials (verified) I get redirected to /wp-admin/profile.php and get "You do not have sufficient permissions to access this page."