Thanks for your attention but I got it by myself.
Here is what to do when the s*t hits the fan:
1) get the recovery CD - this is the hardes part
- go to cisco.com
- browse to the download section do not click directly on "voice software"
- klick one of these locked sections and sign on
- now you can visit the "voice software" link
- without signing on you will be unable to download the CD
- download the apropriate recovery cd
2) burn it
3) boot the broken system from the recovery cd
4) hit "s" for switching partitions when you are prompted
5) reboot
6) done :D
hope this will save another guy some headache