I installed Drupal 6 today on my windows machine in office. After creating the first user I tried to access the Administration Page, but a blank page was returned. I searched google to fix this problem and got this link.
http://www.tmsnetwork.org/blog/content/2008/08/22/drupal-6-slow-administ...
Go to system table and change the value of 'status', 'bootstrap' and 'throttle' to 0