How to remove spyware with McAfee?

I've determined that my pc is infected with spyware. Every link I click
gets redirected, my pc is slow, and there is a note named, problems,
which I did not write. The note says this:



1. you may not connect/perform windows updates

2. you cannot turn off/on your firewall

3. you cant disable your antivirus software



And yes, it was all written in lowercase. I actually went on my