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.
Go to system table and change the value of 'status', 'bootstrap' and 'throttle' to 0
update system s
set s.status=0, s.throttle=0, s.bootstrap=0
where filename = 'modules/update/update.module'
Now you should be able to access the ./admin area :)