Cannot uninstall game downloaded from internet

Question

Downloaded Pool Sharks from the internet & want to uninstall it, but Windows Installer is telling me that the system administrator has set politics to prevent installation & I do not have sufficient access to uninstall Pool Sharks & to contact my system administrator.

Was advised to start up computer in safe mode, chose administrator as my user & uninstall then. Tried this but am then being advised that windows installer is not available in safe mode & that the windows installer could not be accessed & that this can occur if the windows installer is not correctly installed & to contact support personnel for assistance.

Can you help please?