[Typo3] Install tool disappears when upgrading from 3.6

[Marlies C]

We have a strange problem when upgrading from 3.6 or lower to a newer 
version, the install tool disappears and so our access to the database 
analyzer. We can do a manual install on the server side, but it is a pain in 
the but.

Has this happened to others? And how did you fix it? Any ideas are greatly 
appreciated.

Thanks

Marlies
www.enomaly.net