Yes you can remove programs in safe mode. (if it will remove)
Or, you can recover your personal files, make a backup, reinstall the operating system.
Or have a computer shop do it for you.
Don't mess with the registry, it's better to recover your files by removing the hard drive and installing it as a second drive on a working XP computer.
You installed free security downloads? Hows that working out for you?
Once you get it going again, use only a professional all in one security system. This is NOT a free download. Norton, Panda, Kaspersky are the ones you should be thinking about.
Start the computer in safe mode, try to backup your files to a thumb drive. After you backup all your personal stuff, reformat the drive and do a fresh install of XP or win7.