Yay, it works.
By pressing F11 it lead me to a boot menu:
Boot from
1. cd/dvd
2. SATA HDD
3. Infiniti 2.2 TB (I don't know what that is?)
So, I chose #2 and the system boots, WIndows 7 Home Premium is already preinstalled + I have System on the DVD disc.
Evything works. I checked in the properties, it sees all the hardware (hdd,cd/dvd,gpu,12GB RAM).
Yay

Thank you guys, now I can proceed to the next steps of ordering parts for my own build and ordering parts for completing this build. I think it needs fan for the radiator of the CPU liquid fan.
Please advice me on the parts I need to complete this fixing and i will create new thread for my new build.