There are two common reasons for this.
1. When they get the download file and unzip it and go to run the installer, they choose the wrong file. Be sure to run install_RADStudio.exe from the directory where you unzip the install files. If you go into the /install subdirectory and run setup.exe, you will only be running the Delphi/C++Builder IDE installer.
2. They stop after just installing the Delphi/C++Builder IDE (the first button on the launcher) and miss all the other pieces.
The additional buttons on the launcher will vary depending on whether you get the Delphi/C++Builder version of the install launcher or the RAD Studio version. The RAD Studio version has additional buttons for Delphi Prism and RadPHP. Here's what it looks like:
To get the full product experience, be sure to install all the pieces. The numbers below refer to the order of the buttons above.
1. Delphi and/or C++Builder - If you have a Delphi serial number it installs Delphi. If you use a C++Builder serial number it installs C++Builder. If you have a RAD Studio serial number you can choose to install either or both Delphi and C++Builder.
2. If you don't click the Documentation install button after you're done installing Delphi and C++Builder, you won't have any online help available in the product and you'll see an error message telling you the help isn't installed when you try to access it. Run the install launcher again and install the doc from here if your documentation hasn't been installed or visit our Embarcadero Documentation web site for the latest doc updates.
3. The Delphi Prism part of RAD Studio for .NET and cross-platform Mono development doesn't share the same IDE with Delphi and C++Builder so it's a separate install. Click this button to download Delphi Prism. You'll have a choice to download English, French, German or Japanese. Download the installer, unzip, and install using your RAD Studio serial number.
4. RadPHP is also a separate IDE for PHP and Facebook development. Click the button to download the installer .zip file. Unzip and install using your RAD Studio serial number.
5. Use this button to install ER/Studio Developer Edition and InterBase. Your RAD Studio/Delphi/C++Builder Architect edition serial number licenses ER/Studio Developer Edition. Pro and Enterprise serial numbers install ER/Studio as a trial. Your InterBase Developer Edition serial number is available in the installxxx.htm file in the directory with install_RADStudio.exe. Or you might want to download the newer InterBase XE Developer Edition instead.
6. The final button gives you the option to download several additional items. The Remote Debugger is accessible from here as well as CollabNet Subversion Server, InstallAware Express (a free version for Embarcadero customers), and a link to download the Partner DVD with an assortment of free and trial software from Embarcadero partners. (You can also access the online version of the Partner DVD here).
Hopefully that helps answer questions you might have about the installer or install process. Or maybe you've also learned about something new that you didn't know was part of the the product. And now you can be a Delphi install expert and offer help if you come across anyone else reporting that something seems to be missing.