Everything in my laptop keeps not responding?

I've had this Windows 7 64-bit lenovo B560 laptop for 4 years and today sometimes when I click something, all open programs stop responding and I have to restart the laptop and re open them again to work (until they stop responding again) i've tried uninstalling lots of programs, emptying the desktop and closing processes running in the background but nothing works.

The problem with notebooks is HEAT. After 4 years there's probably a huge amount of dust, dirt and fluff clogging up your system devices and your fans aren't working as well as they should. I suggest you find someone who can clean it… Or watch some YouTube videos to see how to do it yourself.

Just purchased one… I really like the looks but just lost 4 hours of work. Not happy right now.