HDD Not Recognised

[Caelanbro]

I just built my new PC yesterday and I have booted up windows 8.1 on my SSD (120GB). I then turned off my PC and plugged in my HDD with SATA and turned my PC back on. I then went into the UEFI and the HDD was there, so I restarted my PC, logged in, and in 'My Documents' only the SSD's data is being shown.. E.g: Local Disk only has 120GB of space rather than 2.12TB. PLEASE HELP ME! I have an ASRock Fatal1ty Z97X Killer Mobo

 

[Suztera]

Your storage does not combine together.
Go to 'Disk Management', right click on your HDD and select 'New Simple Volume'. Proceed with the wizard and afterwards, the HDD should be accessible.
If you use the Window button+S, that will bring up the search function. Type in 'Disk Management' and choose the option "create and format hard drive partition". That should bring up Disk management.