ShowMyPC is a software we use to provide remote support to our users. It uses a service called TightVNC and installs it as part of ShowMyPC.
To uninstall ShowMyPC/TightVNC manually please follow the below steps:
Step 1) Login as Administrator of the PC.
Step 2) Go to Control Panel > Administrative Tools > Services. (It may differ on your version).
Step 3) Locate TightVNC, SMPCHelper, tvnserver and uvnc_service (if exists) and stop them and change the startup type to manual so that they do not automatically start.
Step 4) Restart your PC, next time any services will not start.
Step 5) After restart, remove the folder c:\Program Files\ShowMyPCService and its contents.
The above steps can also be found on the ShowMyPC support website.