Upgrade Wizzard blank page

[lis]

I have installed SugarCRM CE v. 6.2.3 (Build 6658) under windowsXP
When I'm trying to make Upgrade thru Upgrade Wizzard I have blank page.
sugarcrm/index.php?module=UpgradeWizard&action=index

Navigation bar is active only. Below it everything is blank. I tried to clean cache, make fast repair and rebuilt. Nothing happened.
Could you make any idea of solution it?

[gbirk]

I have the very same issue with SugarCRM CE Version 6.1.7 (Build 5875). I to am looking for a solution.