Bought a kingston 480 gb ssd and it works well. Checked how much space i have left and saw that I am using 150 gb with 75 gb left. Checked bios and it told me it was 480 gb. Does anybody know why this is? PC works fine though, build it a few months ago.
If you're on Windows 10, try and open Disk Management and see what it says there. A screenshot would help us two fold. You could also use Easus Partition Master to show you what the drive structure looks like. Also, are you on the latest BIOS update for your motherboard/laptop?
Can you post a screenshot?
Assuming the 'unallocated' space is to the right of the active partition in Disk Management, it should just be a matter of right-clicking on the 'C' partition and selecting "extend".