Nopes. You've to delete install.php and than you can use upgrade.php. I will put a notification in the new version with "If you only want to upgrade HoloCMS, please delete install.php first and than go to upgrade.php."
Sisija
EDIT: New version! HoloCMS 2.0.1 BETA 6. This has over-all fixes and it's easier to understand how to upgrade.
http://rapidshare.com/files/12452649...ETA_6.rar.html
I can code that for sure in housekeeping but if it also has to be work in to the hotel i've to contact Nillus.
Sisija