The first zip file is installed using the Joomla Install method in the Admin back end. Too Easy. It will even tell you when installation has been completed and if it was successful.
The next part is a bit fiddly as you need to unzip the patch file in a folder and then FTP its contents to your website where some 14 Joomla files are replaced by these patched files to enable the Captcha engine to intercept the php script.
Once this is done you simply go to the Joomla Global Configuration manager and SWITCH ON the component. I must admit I did have an issue here as after successful install the option to switch on the component was NOT showing up. After a few hours researching I simply unzipped the patch file again and used FTP to upload the files again. This time it worked!!
The Security Images component has a very powerful and useful back end configuration menu which not only allows you to make configuration changes but also has very useful troubleshooting options. Also there is a range of different Captcha core or plug-in supplied that give you lots of different options to display graphical letters.
On the front end it works very well and integrates well with the register,login and contact pages.
I believe when Joomla V1.6 is released the installation will be even easier as the patch files will no longer be necessary.
Overall 10 out of 10 for this fine product.