banjulbell,
What is the make and model of your PC?
PC-Doctor is installed by many OEM's at the factory. It is a hardware diagnostic tool that is used by support and end users. If I know what make and model the system is I will know how PC-Doctor is installed on that particular system.
I have seen cases where, when done as a preloaded by the manufacturer, it does not appear in the add remove program list. Most often the easiest way around this is to download the newest version from your OEM and install it. It will then appear in the add remove programs list and can be removed normally.
If you want to do it manually there will usually be a uninst.exe file in the application directory, running this will un-install the program. What the application directory is named depends on your OEM.
-Fred