Did you disable UAC (as advised in the
How to reinstall PostgreSQL guide) or run the command prompt as Administrator?
Right click Command Prompt in the Start menu and choose Run as Administrator and try it again, or read the linked guide which walks you through everything you need to do.
If you still can't get it sorted please url=https://www.pokertracker.com/support/newticket.php?cat_id=178]schedule a remote assistance session[/url] where someone can logon to your computer with you and directly troubleshoot/resolve the issue.