New PSU, message "Reboot and select proper boot device"

[Jayrod9121]

I recently installed a Rosewill 750w Capstone PSU to my rig and I am getting a message that pops up after my BIOS settings that tells me to

Reboot and select proper boot device
Or insert boot media in selected boot device and press a key

My rig already had Win7 installed to my C drive (an SSD), and I have already set the SSD to my #1 boot priority in BIOS. This still happens. All my SATA cords are set up, 24pin connected to motherboard, 4 pin connected to motherboard, and 2x6 pins connected to GPU.

Is there any way to overcome this problem in bios, or do I need a "boot media" (I'm guessing would be my Win7 disc)?
This is the first time I've rewired my entire rig to a PSU, so I'm a little bit confused.
Thank you for reading this.

 

[shortstuff_mt]

If the system was working before upgrading the PSU then it sounds like the power connector or SATA connector for the SSD is not fully inserted.

 

[ko888]

When you enter the BIOS Setup do you see the SSD listed? If it isn't listed in the SATA devices then the SSD isn't being recognized. It may be due to a SATA power cable not being connected (or loose) to the SSD or the SATA data cable is not connected or not making proper contact or is defective and not making proper contact with the SSD's SATA data connector.