It is not a replacement for a full antivirus suite like Bitdefender or Kaspersky , as it doesn't actively block incoming attacks.

One of its most useful tools is the ability to reset Internet Explorer/ Chrome /Firefox settings that have been hijacked by malware (e.g., changed homepages or search engines).

If your PC is heavily infected and you can't run the installer, download the Portable version on a clean computer first, then run it on the infected machine. Are you dealing with a specific virus right now, or