Yep - I made myself a fool...
Yesterday I noticed my system-hard drive to be nearly full. But I need to install some programs, so I decided to delete some stuff I "don't use anyway". One of them was MS Office. I'm using Open Office for all kinds of documents and have no need for MS Office. Now, one day later, I notice that I'm actually using MS Office - I use the Outlook Email!
Damn, so I will have to reinstall MS Office and hope for my mails to be still available. But I've used Outlook today, it might not have been uninstalled completely as it was running all the time in the background.
need to search for the pst-file right NOW...
EDIT: luck is for dump people...Ii installed a backup-system for the pst-file some time ago
regards
Torsten