Windows System Administrator's role :

The system administrator is responsible for following things:

1. User administration (setup and maintaining account mainly active directory).
   
2. System Setup and maintaining system.
3. Verify that peripherals are working properly.
4. Quickly arrange repair for hardware in occasion of hardware failure.
5. Monitor system performance.
6. Create file systems.
7. System log monitoring.
   
8. Install software.
9. Create a backup and recover policy.
10. Monitor network communication.
11. Update system as soon as new version of OS and application software comes out.
12. Implement the policies for the use of the computer system and network.
13. Setup security policies for users. A sysadmin must have a strong grasp of computer security (e.g. firewalls and intrusion detection systems).
14. UPS management.
15. Server security monitoring.