My laptop works very slow

I have a 3 year old Toshiba Satellite (bought new) series P15-S420. It used to do everything at super speed. Now it is very, very slow! I’ve uninstalled all my heavy programs that I added on (like Photoshop, games, etc…) and there has been no change! My husbands HP has an accelerator control. Does Toshiba have one hidden somewhere? Any ideas and or advice from anyone would be helpful! Again thanks for any and all help.

Usually a laptop works very slow because of the three following problems.
1. Installed spyware or adware programs consume a lot of resources and slow down the laptop. Open up the task manager (right click on the task bar) and check the CPU usage in the performance tab. From my experience, the CPU usage might vary 0-10% when the laptop is idle. If it’s constantly over 50%, then you might have some malicious software installed on your laptop. You can try to clean it with an adware/spyware removal tools, for example spybot. Sometimes it’s very hard to get it completely clean and in this case I would recommend restore the operating system back to original factory defaults. You can restore the factory defaults if you boot the laptop from a recovery CD or DVD. Before you run a recovery CD/DVD, back up all important data from the hard drive because it would be erased and reformatted during the restore process.
2. The heat sink is clogged and the laptop overheats. If the laptop heat sink is clogged, the CPU overheats and it might cause the entire system to slow down. It’s very easy to check the heat sink on Toshiba Satellite P15. It is not necessary to remove the heat sink if you want to clean it up, you just have to remove the fan and clean the heat sink with compressed air.
3. The hard drive is going bad. Turn on the laptop and listen if the hard drive makes unusual noises (clicking, grinding, etc…). It’s possible that a laptop will run slow if the hard drive is bad. In this case you’ll have to replace the hard drive and reinstall the operating system. Sometimes the hard drive might be bad even if it doesn’t make any strange noises. You can test the hard drive with Hitachi Drive Fitness test.