Booting from DVD with RAID

[DCVVCD]

Dear all,

I have old PC whose hard drive stopped working. I installed new HDD and I have bootable Windows DVD, but the problem is that it cannot boot from the DVD. Both the hard drive and the DVD reader are registered on start. The only option that is available on start is RAID menu and there I cannot modify the device it boots from - which is by default the empty HDD. Usually I do that in BIOS settings, but there is no option to enter BIOS during start (or I am not aware that it exists). What do I do? All I get after start is the empty screen with instructions that I should insert bootable media (and there is bootable DVD in the drive)?

 

[WyomingKnott]

What kind (make and model) of "old pc" is it? And what mode are the disk controllers set to? Is the hardware SATA or IDE?

 

[DCVVCD]

It is SATA. It is old, from 3-4 years ago and I want to make it usable as a backup.

 

[DCVVCD]

It used to work with other SATA drives, so there is no change in that.