My laptop is very slow, used to be fast

Save you personal documents and do a factory restore or full manual install, then all your windows updates.

re install windows and update all the drivers. your computer slowing down can be cause by how you use it meaning you can start installing different programs on it and never use it clogging it up with unecessary stuff. the more software you have installed more of them automatically start when windows starts so try to keep your windows tidy and only have stuff installed that you actually use, when installing software read carefully not to install extra stuff and some tool bars as all that stuff slows down your pc

where did you get the games? it a laptop, it probably overheating

Helpfull if you provide Laptop Model and if it has a dedicated GPU.

a quick and easy step before a windows re-install would be to download CCleaner and do a registry scan to see if that is the culprit. Then do a malware scan with Malwarebytes http://www.malwarebytes.org/

hope this helps

Definitely want to try giving it a thorough cleaning with compressed air since overheating (as stated above) can cause the CPU and GPU to throttle.