Nothing is ever "completely" safe. Any malware or antivirus utility could have undesirable effects on your system if you have questionable software installed and allow it to remove some portion of it. Obviously, there are other scenarios where it could also be bad, but overall, you can usually find most issues with the main players.
Norton and Avast are severely bloated and IMO mostly worthless.
I would recommend that you check that your definitions are up to date, and run those again. Then, download the free version of Malwarebytes, and run that.
Honestly, you don't even need either of those utilities, Norton or Avast. The build in Windows defender does just as good of a job these days as those do. And will a lot less resources involved. After running Malwarebytes I'd run a system wide scan using Windows defender.
If none of that picks up anything, then yes, I'd try running Roguekiller but I would not allow it to delete or quarantine anything unless you are fairly sure, after checking the process or filenames against known infections online, that you know what you are approving.
Below you will find not a highly technical How-To, as there are plenty of those across the web, but instead an easily referenced resource for less technically astute members or visitors who simply want easy provision of resources related to the discovery and removal of infections in a variety of...
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