Problem: Laptop freezes during start-up, BIOS or CD/DVD can't be accessed
Solution is to remove HDD, connect it via adapter to working PC,
Control panel - Administrative Tools - Computer managment -
Storage - Disk manager - Delete, reformat disk.
It had 2 partitions
which were created during Windows 7 instalation.
They are the cause of this problem,
which appears falsely at first as invalid MBO, HDD or BIOS.