So you are suggesting throwing random tools at the problem without even knowing if there is one? Scareware does not hide. (Yes I am aware that scareware is not a technical term, but it fits the situation nicely.) That type of malware likes to show itself constantly. If it where installed locally, it would have shown itself by now. But, if you want to be sure, lets do some basic tests before tossing random tools into the mix.
If you are still worried about this, than its not a problem to start looking for. If so, then lets start with Hijack This, and work our way out from there. Please download Hijack This from here
, and install it. Once it is installed, the first button that you will see will be at the top and says "Do a System Scan and Save a Log File". Click on that, and it will open the log in notepad when it has finished. (This process takes very little time.)
Please post the resulting log file here to be analyzed.
It never hurts to be sure, and this type of check will allow us to look for other things installed as well.