[horde] Administration site has gone

[Support ETS Uni Bonn]

Hello,

i have made a  big mistake installing Horde3 with IMP. After configuring 
Horde in the administration site i can only log in to IMP.  If i go to 
the site http://server/horde it switchs automatically to 
http://server/horde/imp/login.php
Does somebody know how to reconfigure HORDE to log in to the 
administration site? TIA