How to set Fixed IP

I am using dynamic IP in my server now, how can I set Fixed IP? 

Solution:

1. Go to Network --> Right click --> Properties --> then you will see "Network and sharing centre" --> Click on Connection  

2. it will pop up "Ethernet Status" --> Click on Properties --> then cursor point to "Internet Protocol Version 4 (TCP/IPv4) --> Properties

3. Follow below setting but IP address can be optional example 192.168.100.108  
Note: Before you apply this setting please inform users not to use the Internet first