How to Upgrade client tier-only installation to Version IS 8.5

As enterprises are migrating to Information Server version 8.5 I thought of  covering few basics.
Existing Client Tier can be upgraded using IBM InfoSphere Information Server to Version 8.5.
Complete all preparatory steps as described in Preparing to run the installation program 
In case installing Metabrokers and Bridges as well, remove their current installation before upgrade started

To upgrade client software directly by using the installation program, InfoSphere Information Server server-side software must not be installed on the computer. To retain existing client versions, you must select a different installation directory location for Version 8.5. You can upgrade your client software at any time before, during, or after installing the server-side software on other computers.
To upgrade a client tier-only computer, use one of the following two scenarios:
 Procedure
  1. Start the installation program in graphical mode as described in Starting the installation program in graphical mode
  2. Follow the prompts in the wizard as they appear.
    When the installation program detects that the target directory contains a client installation, confirm that you want to upgrade the installation. Based on your settings, the installation program runs a prerequisites check. During this check, it analyzes the resources and file system of the computer to determine whether the new client installation is likely to succeed. The wizard page displays each check. If the prerequisites check fails, it is marked FAILED for the corresponding items.
  3. If you receive a FAILED message, double-click the message to learn more about resolving it.
    If it is necessary to exit the installation program, click Cancel and close the browser window. Resolve the issue and then restart the installation program.
  4. The installation program summarizes your settings and then begins the installation.
  5. Monitor the installation as described in Installation progress monitoring.
    Leave the terminal window open until the installation is complete.
  6. After the installation is completed, install the correct Microsoft XML Core Services (MSXML) Service Pack.
  7. Repeat the upgrade process for each client computer
If the installation fails:
  1. View the installation logs for more information. See Log files.
  2. Resolve any issues that are listed in the installation log files.
  3. Remove the installation directory structure and the installation log file.
  4. Run the installation program again. 
Working on a detailed Step by Step approach for Migration and share in couple of weeks
-Ritesh