Bogging down the whole system

I have installed Total Security package on a Dell Inspiron 15-5577 with Windows 10. Been bogging down for over a year. Thought I had a virus. Wiped hard drive and reinstalled Windows and BitDefender. Still Bogging down. Thought it was my RAM. Upgraded RAM. Still bogging down. Thought my hard drive was defective. Installed a new M.2 hard drive. Worked amazing! Right up until I installed BitDefender was reinstalled.

Anything that can be done before they lose a customer?