I am using McAfee Total Protection since long, almost more than 8 years. This is the first time on 22/07/2020 I found that my PC with Windows 10 Pro version 2004 was behaving in a abnormal way. I could not find any security suit, error message was appearing on every restart, stating that "StartupCheckLibrary.dll" was missing. After searching web finally I found that file was quarantined by McAfee. I faced this issue for the first time. I have to reset my PC to get everything alright.