I've had quite a few so called Technical Support people ring me in the last few days. They are claiming that they aren't selling me anything and that they aren't trying a scam. As usual, the caller has an Indian accent and a UK first name. They claim that there are programs on my computer which shouldn't be there and that anti-virus and malware programs won't pick them up. I don't let them get very far before I cut them off.
One of them wanted me to run EVENTVWR. These scammers almost always try that one out as the resulting screen will always show lots of errors. That one is well known.
But the one just now tried a different tactic. In the run box he wanted me to type INF HARMFUL FILES. I cut him off at that point. Typing that command is harmless. All it does is to open Windows Explorer and show the files in the C:\Windows\Inf directory. The HARMFUL FILES bit is meaningless, you get the same result whatever to type. The directory contains the files used in installing Windows in the first place.
Another command sometimes used by the scammers is PREFETCH. Again that just shows the files in the Prefetch directory.