What will happen if i back up and restore system settings?

If you restore your system settings it will not erase your system files, it will just restore the settings back to an earlier point if it was backed up. This sometimes can fix registry problems and auto-run issues. If the problem persists, you may have to do a complete system restore which WILL erase everything. There is usually a utility that can be accessed for this in the start menu or the system bios.