Download Oracle Database 12c Release1(220.127.116.11.0)
Go to www.oracle.com Register yourself, otherwise you will be asked to register your details before downloading oracle database.
Go to http://www.oracle.com/technetwork/database/enterprise-edition/downloads/database12c-win64-download-1968077.html. There you will find the links for downloading Oracle Database. Refer the following diagram.
Before downloading these two files check whether you have basic infrastructure to download these two files. (High Speed Internet, Disk Space, Memory, Operating System etc.)
You can use www.internetdownloadmanager.com/download.html to download the files in a faster way.
Since we are using Windows 7 as our operating system and 64 bit, we have downloaded the following two files.
Since files are zipped, unzip those two files and store it in the same directory. We used WinRAR to unzip those two files. If you have stored your files in c drive, then you can see Oracle Universal Installer (OUI) file in the following directory structure C:\Oracle\database\install. Oracle Universal Installer is used to install oracle with different options.
Now Double click that OUI. Now you will see the following screen.
Now OUI wizard will open up and will guide you through the entire installation process of Oracle 12c. Refer the following steps.