"1603 - Fatal error during installation" encountered when installing TOAD for DB2 (4270191)

"General error occurred return value is 1603" or "1603 - Fatal error during installation" warning given when trying to install TOAD for DB2.

CAUSE 1:

The user does not have proper admin authority on his PC to run the installation.

CAUSE 2:

.NET Framework system requirement is not met. 

RESOLUTION 1:

User needs full admin privileges for instalaltion. Verify privileges with the system administrator. Verify UAC setting. 

RESOLUTION 2: 

Ensure the .Net Framework versions are installed properly. Check the specific version's system requirements for .NET in the release notes here.