Run System Restore and, before re-installing your downloads, check that everything's OK.
Decide which anti-virus program you want on your PC. (You should never have two ant-virus programs running simultaneously. It's asking for trouble). If you want to use something which you've just downloaded, uninstall your existing anti-virus program (and reboot your PC) before installing the new software.
Re-install one dowload at a time, ensuring that you close all Windows programs before each installation and also rebooting after each installation.
Now cross your fingers and pray that Mr Gates' rubbish operating system is going to work as it should do!
Chris