Each and every time I run a scan, it shows 15 infected files.
It's the exact number every time, and even if I run it consecutively.
Obviously I know I'm not getting exactly 15 infected files in between both scans which were minutes apart. Is it just finding 15 infected files, but not doing anything with it ?

The ClamWin scan report shows where the files are on your computer. The default option is to report infected files only. You can set the option to quarantine or remove (be careful). I prefer to have ClamWin report only because once in a blue moon, you get a false positive. If the false positive is on a Windows system file, you could lose access to Windows if it is placed in quarantine or removed. The option is up to you. If you want to change it, go to ClamWin's configuration options. On the general preferences tab, you can change the options in the Infected Files section.

You should probably verify any file is infected before you do anything with it. Find the file on your computer (from the scan report) and upload it to Jotti or VirusTotal. Either one will scan the file for free with multiple AVs, including ClamAV, which provides the scanning engine/signature database to ClamWin. My rule is if more than 5 other AVs besides Clam find the file is infected, it is not a false positive, and you can remove/quarantine it. If it is a false positve, and you have used the file/program for a while without any ill effects, upload the file to Clam via their submission page and tell them it is a false positive, so they can adjust their signature.

Regards,