Check if any program is secretly reading your saved WIFI passwords or not?

In general, rely on the integrity of the applications you’ve installed (and on keeping your machine physically safe from installation of malware, e.g., while traveling). It is possible for an application, such as Nirsoft’s WiFi Key View, to read the cached passwords in Windows. Before installing an application, check it with a few anti-malware tools, such as through VirusTotal.

However, why is this of concern? Your WiFi password is only useful for a particular router, and simply allows communication. Do you believe someone is obtaining free WiFi that you are subsidizing? Id so, contact your ISP.

Note that the password does not identify the user, and, for most networks, even those with WPA2, is not impossible to obtain remotely. For WPA2-PSK (AES), more often used in enterprise networks, there would be some advantage to a hacker finding the passkey on a machine, though.