Even if you got the latest and the most perfect operating system, sooner or later weaknesses will be identified by hackers, malware and by the developer itself. All operating system start to have security issues not much time after they are released.
Security issues have been identified even in ActiveX controls that could allow attackers to get easy access in your system through internet explorer.
Security issues are identified regularly everywhere, in systems code, in apps from system in new updates that need to be updated again. Even if you have an antivirus program or anything else you must get updated, an antivirus will not save you from operating system issues.
If you will not install at least the security updates, you can get data loss, malware, viruses, software damage, operating system damage. Once the update is available, you should immediately install it, or better to leave the updates on Automatic. In the most cases after updates you will have to restart your computer.
Note! It doesn’t mean that you should not have an antivirus installed! You must have an antivirus installed. The difference between security updates and antivirus is that antivirus can catch the most current viruses which are spreading with the speed of light. The system security updates can fix your system security issues, stop some viruses that antivirus can’t stop. Also it is responsible for all the system and the components that have to maintain the system.