Download Complete Steps with Screen shots

High Level Steps

1. Install Windows 2012 Server.
2. Check and Apply Pre-Requisites.
3. Add Node from GRID Home from Existing Node and it will copy Grid Home to New Node.
4. Execute Grid Config on New Node  
5. Add Node from Oracle Database Home from Existing Node and it will copy Oracle Database Home to New Node.
6. Add Instance of Existing Database to New Node.

Steps for Node Addition

1. Turn off and Disable Windows Firewall                                                                          (New Node)
2. Add Network Adapters Public and Private                                                                     (New Node)
3. Change Adapter Type to Bridge                                                                                     (New Node)
4. Change Name of Adapter According for Existing Nodes                                             (New Node)
5. Define IP Address on Both Adapters                                                                              (New Node)
6. Change Host Name According to Existing Nodes                                                          (New Node)
7. Define New Node Public Id, Private IP and VIP IP Name in Host File or DNS       (All Nodes)
8. Ping New IP Host from All Nodes                                                                                   (All Nodes)
9. Start NFTP Service and Set Auto Start.                                                                           (New Node)
10. Disable Windows Media Sensing (DisableDHCPMediaSense)                                    (New Node)
11. Connect with Database Storage.                                                                                     (New Node)
12. Online ASM Disks.                                                                                                           (New Node)
13. Set Attribute of Read only Clear for All ASM Disk.                                                       (New Node)      
14. Adding a Node to a Grid Home                                                                                      (Node 1)
15. Execute Grid Config.                                                                                                        (New Node)
16. Post Verify Grid                                                                                                                (Node 1)
17. Adding a Node to an Oracle Home                                                                                 (Node 1)
18. Register New Node Virtual IP                                                                                          (Node 1)
19. Create Instance on New Node of Existing Database                                                   (Node 1)

Existing Database Nodes Configuration

Operating System: Windows 2012

Database Cluster Nodes              = 3

Scan Name                                     = nodescan

192.168.18.151               Node1

192.168.18.152               node2

192.168.18.147               node3

192.168.10.151               node1priv

192.168.10.152               node2priv

192.168.10.155               node3priv

192.168.18.153               asmstorage

192.168.10.153               asmstoragepriv

192.168.18.145               node1vip           

192.168.18.146              node2vip

192.168.18.148               node3vip

192.168.18.241               nodescan

192.168.18.242               nodescan

192.168.18.243               nodescan

NEW NODE Configuration

Two Network Adapters for Public and Private

Public Interface Name   = Public

Private Interface Name = Private

Host Name                       = Node4

192.168.18.149               node4

192.168.18.150               node4vip

192.168.10.156               node3priv