It sounds like the issue you're facing with the slow performance on those two PCs might be due to low storage, outdated drivers, or some background processes that are using up resources. A good starting point would be to try Advanced System Optimizer or CCleaner to clean up disk space, update any outdated drivers, and optimize the system overall.

Also, I came across a review of a good PC optimizer that might help you. If you're interested, I’ve attached the link so you can check it out before using. Feel free to reach out if you need any help!