Actually this is the results of being infected with different viruses. These programs protect themselves by denying any known applications from being installed that will locate and remove them. This is why it is so important to install antivirus programs as soon as possible.

About the only option you have left is to try to install the antivirus during safe mode and running it from within safe mode to clean your system.
If that is not possible then you must reformat and reinstall your system to rid yourself of the problems.

To enter safe mode:
restart your computer and immediately start toggling the F8 key until the start up page opens. Choose to start your computer into safemode. this may take awhile. You will have successfully entered safe mode if your desktop is shown with safe mode shown in the corners.

well it won't let me install the software on safe mode.

your computer is already infected with virus that's why whenever you install
an anti virus. the virus itself shutdown your system.. go to safemode like lurkswithin said and try to install antivirus. if it will not work then you nedd to reformat your laptop and install an antivirus immediately.. hope this will help you. thank you. God Bless You..

you might have an installed anti virus. try to uninstall it first or if security center try to disable it.