uninstallation.html definition, relationships, removal:

PC Activity Monitor malicious parasite that violates user privacy and damages the compromised system. The uninstallation.html file can be used for different purposes depending on the related parasite's type, functionality and carried payload. Although uninstallation.html may not take any malicious actions by itself, it ensures that a parasite is working properly and therefore needs to be removed. DO NOT open, execute or edit uninstallation.html!
The uninstallation.html file is installed and used by keylogger PC Activity Monitor.
Please note that the uninstallation.html file actually may be a fully legitimate part of the operating system or legitimate software. Often parasites use files with unsuspicious names, but malicious functionality. You should always carefully check the file before deleting it. It may not be related with malware, but can be required by your essential programs to work properly.