Safety Scanner found 12 infected files but scan results said no problems detected

I have used the MS Safety Scanner for somewhere in the vicinity of 15 years. The scan reports always have stated what the OP describes. I have always had my suspicions that the scanner does find more and removes more malware than what it states. My desktop has been doing weird things for awhile. Slow. My ESET says everything is fine. I downloaded this scanner and let it work. It scanned overnight. In the am, scan is almost done finds like 25 issues. It ends and the report states nothing was found. But now, my desktop is back to its normal behavior. Apps start faster, switching apps is faster, weird links popping up in the address bar. All of that is gone. This scanner removed something. I suspect that there are more malwares in the wild than any of the IT people want to admit. This is just the MS way of removing them.

I totally agree with the answers above that the wording is confusing and should be changed. Secondly when the scanner is doing it's mapping step if you have a large number of "Infected files" (I had over 400) the scanner seemed like it is stuck because the file counter stops. I restarted my scanner a second time in safe mode because I thought the first time, which took more than 2 days, failed. There could be a message added to indicate what was happening during the mapping step so users would not assume that the scanner had stopped or was stuck.

Agree with @John Clegg and @Jon M above. The tool should also enumerate the identified "suspicious files" to allow further investigation at the user discretion.

I agree with @John Clegg here about the contradictory messaging. The scan progress screen should show "Suspicious files: 12" -- not "Files Infected: 12"

Additionally, based on the description @Anonymous gave of what the tool actually does, the description at the top of the scan progress screen should be modified to say something like this: "After this operation completes, the tool will send any suspicious files to Microsoft to determine if they are viruses, spyware, or other potentially unwanted software and report the results."

That would reassure users that the suspicious files will be further evaluated to determine if they are actually infected, so the final result of no infections will not be so contradictory that it leads to posts being created on Microsoft forums.

And since I'm already in here giving unsolicited advice about how to improve an already useful tool, it would be helpful if there was some indication of what it is doing when it starts the progress bar over again. Even if I start it on a scan of just the C drive, it seems to scan it multiple times. I assume it's using a different heuristic each time or something, but a better indication of how many heuristics or how many scans it needs would be nice. That would help me to estimate how much longer it will take to complete. The full scan takes all day on my computer with tons of files, so that extra indication would be very informative.

Danny, your answer is just silly.

What is wrong with Catwoman-3559's screenshots are that the first one says "Infected files: 12" and then the second one says "The scan completed successfully and no viruses, spyware, and other potentially unwanted software were detected."

These two pieces of information directly contradict each other and simply don't make sense.

MS could easily correct this confusion by changing the verbiage in the initial screenshot to “Possibly" Infected files: 12” or "Potentially" Infected files: 12" AND something like "Please see final "Scan results."

-John