Avoid doing that—it can't help, and may well cause problems since you're not familiar with making it work.
Trying to interpret your setup, is this correct?
♣ You have a new PC with Windows already installed and working;
♦ You have a SSD from an old machine which also has Windows on it;
♥ You don't plan to use the old PC anymore.
If that's your situation:
♣ Delete Windows from the old SSD—format is best, but delete will work;
♦ Note that format will erase everything on the old SSD, so if you have personal data—images, documents etc—you need to copy that elsewhere first;
♥ Windows installs a lot more than just the Windows folder, so deleting rather than formatting will still leave a lot of useless stuff behind—but it shouldn't cause any problem other than wasted space;
♠ Install the old SSD in new PC and use it to store personal data and games.