In case the Setup Program fails to install the Smart Client on your computer it will try to roll back all changes that it made so far to your computer system and will then inform you about the installation failure.

If you are not able to detect the cause of the installation failure you should try to run the setup executable from the command line with the logging option applied.

"<SetupExeFullPath>" /L*V "<LogFileFullPath>"

An example would be:

"C:\SomeDirectory\Setup.exe" /L*V "c:\temp\InstallationLog.txt"