Ok so I'm attempting to use a hard drive from an old laptop that still works on my new laptop and the old hard drive works perfectly fine on the old laptop but says there isn't an os on the hard drive when I put it in the new laptop any suggestions?
You cant move an os from one system to another and expect it to work. More often than not it will not boot or will be unstable. If you want to use that hdd in the new system you'll need to do a clean os reinstall.