It is not a maze for people who are used to support EEPC product for some time.
I assume that you are authorized to download products from McAfee and have valid product grant number. Download from here:
Thank you very much for your help, Peter! :-)
Unfortunately, I have contacted my company's IT again and according to their representative: The company's policy is to reimage any PC with this kind of problem and not to try to recover the data. They don't even seem to have the grant number or anything like that! :-(
Oh well... time to format and reinstall.. :-(