Welcome to Anvisoft forum and thanks for posting your problem here. I am Ivy and I am going to help you with your problem.
A slow computer can be caused by too much computer system junk files, trojan virus or any other factors. I recommend you do following to fix your problem.
1>Clean off computer junks that including browser cache, temporary system files, and registry number of invalid registry entries.
You can take the free junk files cleaner, Cloud System Booster to remove any types of junk files.
Direct download link:http://www.anvisoft.com/product/cloudsystembooster.html
2> Check the presence of malware, trojan, virus. Trojan viruses scanning in the background which collect information and may also take up too many system resources that resulting in the case of computer slow.
I would like recommend you take Anvi Smart Defender to run a full scan for virus check.
Direct download link: http://www.anvisoft.com/product/smartdefenderpro.html
If you are still experiencing the same problem, please let me know. I will try my best to help you.