Do the webserver logs say something meaningful for you?
If using Apache (available for Windows also), the apache logs would normally say something meaningful, when tiki displays a fully blank screen.
Ensure also that when you install Tiki you enable Tiki to display the errors amb warnings to the users, for all users (no only admins).
If you could login as admin, you could also apply the profile "Debug_Mode_Enabled" (available from the Tiki Setup Wizard for 'Configuration Profiles' also)
you could also mimic the profile by adding those values included at the profile into the tiki preferences table.
(a pitty Tiki doesn't work out of the box for your use case; I wish more people had tested Tiki in that working environment, but it seems it may have not been the case; your input and feedback will be very welcome)