Samsung 840 evo ssd not showing. Installed in optical bay on Dell precision M4800 any ideas?

[shaady]

I have a Dell precision M4800 and I installed a 840evo Samsung ssd in the optical bay. The problem is when I turn on the computer before it boots to the desktop it shows both HD's. I have it set to AHCI. When it boots to the desktop and I go to "computer" only one drive shows (I have two 1TB 840 evo's) Can anyone help me with this?

 

[clutchc]

Go to Computer/Manage/Storage/Disk Management. It may need to be made active.