1. Power on your system. Press the appropriate key, typically ESC, F12, or DEL. If a boot menu isn’t available, you’ll need to adjust the boot sequence in the computer BIOS, which you can then use to boot directly from your selected media. Set your computer’s BIOS to boot from the first installation CD or USB drive. Details vary by PC. Make sure your BIOS saves your changes before you reboot.
2. You’ll see the first installation screen. Click Next.
3. You’ve already selected a language and keyboard, so the next step, if you’re actually running Red Hat Enterprise Linux 5 (as opposed to one of the rebuild distributions), is to enter an installation number associated with your purchased or trial subscription, as shown Here
4. Partition configuration based on your memory and available hard disk space (based on free space after removing partitions), or choose to customize the configuration
5. If there are existing partitions on the installed hard drives, you’ll get the chance to confirm that you want to remove said partitions (this step isn’t final). If you’re configuring a dual-boot with another operating system, don’t delete the partitions! Instead, click back and select Create A Custom Layout.
6. Now inspect and change partitions in Disk Druid, as shown. You can also create and then configure RAID and LVM partitions. And Then Click Next.
7. Once you’ve configured your partitions, set up a boot loader. If you select No Boot Loader Will Be Installed, you’ll need to use a third-party boot loader such as Partition Magic or Microsoft’s NTLDR. Unless you want to set up a Boot Loader Password or Configure Advanced Boot Loader Options, click Next.
8. Configure your connection to the network. If you don’t want the DHCP server to assign a hostname (or you don’t have a DHCP server), you can assign it manually, as shown here. Click Next to move on.
9. Set the time zone for your system. If you don’t have another operating system on this computer, keep the System Clock Uses UTC option active. Then click Next.
10. Type in and confirm the root password for your system. Click Next
11. There are two package customization screens available. Click Next
12. Select the package groups of your choice. This should conform to the requirements of the Installation and Configuration section of your particular packages. Click Next.
13. Once you’ve selected the package groups of your choice, you get one last chance to go back before starting the installation process. Click Next if you’re happy with your choices, or click Back to make changes.
14. The next screen congratulates you for completing the installation. The next step is to reboot your computer into RHEL. Click Reboot.
Hope the Above Redhat enterprise Linux 5 step by step installation. If you have any question or query ask at any time.