Hey there, maryammd88!
I'd re-seat the SATA cable the HDD is plugged with as i7Baby suggested first and reboot.
If this doesn't work, I'd recommend connecting the HDD to another computer or trying with a different SATA cable.
Is this your primary and only HDD in the system or is it a secondary drive?
Go to BIOS and look at the SATA ports, check if they are Enabled this might be the reason why BIOS isn't listing your HDD as well.
Share more details about your computer and storage, so that we'd be more useful.
Try these couple of troubleshooting steps though, they might fix the issue.
Keep us posted!
SuperSoph_WD