I had a similar problem, though not as scary as yours. My PC would reboot less often, and was per time but per activity, but it was definitely tied in with CAVS Beta 2.0.17.58.
I also had very sluggish opening of all programmes.
I g=had another AV programme installed: AVG AV. I closed it down before installing CAV. However I only managed to stop the crashibg by actually uninstalling AVG AV before installing/running CAV 2.0.
I now do not have slowdown, and so far (30 minutes) no crashes.
Something to try if you are willing to go back through Linux if it does not work.
However, follow
https://forums.comodo.com/help_for_comodo_antivirus/will_free_comodo_antivirus_detect_spyware-t20071.0.htmlNick