Hi !
PS If I had your PC in front of me I would try these things first.
Down load and run Malwarebytes.
https://www.malwarebytes.org/free/
Then I would scan it with ESET,MSE, and Tread House Call on line scanners.
Here's ESET on line scanner.
http://www.eset.com/us/online-scanner-popup/
Here's MSE on line scanner.
http://www.microsoft.com/security/scanner/en-us/default.aspx
You can also type MRT in search and run Windows deffeder.
PS McAfee Is not my favorite Anti-Virus protection, but that's a choice you have to make. 85% CPU is not right. Here's my Task Manager while I'm typing here on the forum. I use MSE and it is using 0% to 2% at this time.