I doubt that it is your operating system. I have been having problems getting onto RV.net from time to time over the past week or so. Same issue with either my Win 7 desktop or my Win 10 laptop. Sometimes I can get on through Woodalls, sometimes not.
No personal experience with PC Matic, but I wouldn't trust anything that claims to "speed up your PC". You may want to read some of the PC Matic reviews
here. If you want virus protection, try the free version of Avast. We also use Malwarebytes.