You mean a blue screen of death BSOD?
You don't mention any details but I will assume you are a home product user.
Make sure Windows is updated fully.
I suggest uninstalling all McAfee via Control Panel > Programs and Features
Reboot if asked to.
Then run the MCPR cleanup tool and reboot.
Reinstall the software from your online account.
You have not been using any *Registry Cleaners* I hope. They can wreak havoc on the Windows registry.
Blue Screen of Death
Computer Screen are most commonly caused by corrupted or missing dynamic-link library (DLL) files. Errors related to it usually occur when a program mishandles the file during use. The most common problem happens within the Windows registry, where applications look up the location of DLLs they need. And because these are critical files, when one becomes unavailable, there's no telling what could go wrong.
Most commonly, you will experience program lock-ups, slow PC performance, system freezes, blue screen errors, startup or shutdown problems, and installation errors. In the worst case, if the DLL is required by Windows, your entire system could become unstable.