Can't install CentOS 6.9 in a 80GB HDD

[punktuga21]

Hey there, I got two HDD's in a server, one with 300GB and other with 80GB. I want to install CentOS in 80GB HDD but when I'm going to do it, I only got the 300GB HDD available with the 80GB HDD missing. I checked on the BIOS and the two HDD are available. Any help please?

Note: I got Windows Server in it that I want to remove

[avij]

Please don't open multiple topics for the same problem. Let's keep the discussion in the other topic.