I'm not sure. After I had deleted the malware entries in the registry, I started installing the programs again. Windows Defender was the last program I tried to install before the computer got stuck in a reboot loop i.e. it would load windows partially then shut down before it loaded everything. It got stuck and I couldn't fix it until I did the system restore. Then after I had restored all I could, I installed Windows Defender then moved the set up files to the recycle bin. After that, it got stuck in that start-up loop again and I had to go back and do another system restore.