I have an SSD from an old macbook pro lying around. Can i use it as the primary drive for the windows PC I'm building (after installing windows on it like a normal new SSD)? Do i need to do anything to it or is it just plug'n play?
You would first need to install it as a secondary drive and format it(NTFS) before you could use it as the main boot drive or secondary storage drive.
Yes, you can use it but no it won't be a simple plug and play. If you have 10 on a disk or USB drive it might allow you to format it during the install process. Make sure it's the ONLY DRIVE installed if you try that route.