When the customer installed IBM SPSS Statistics 20 which runs fine, and installed R 2.12 completely, there is error below when install Essentials for R:
"R 2.12 was not found on this computer. Please install R 2.12 on this computer and run this installation again."
During the installation of R 2.12, you have to select the installation folder under the same main folder as the IBM SPSS Statistics program.
For example, for Windows 64 bit, the default installation folder for SPSS Statistics 20 32-bit is 'C:\Program Files (x86)\IBM\SPSS\Statistics\20', so you need to select the R 2.12 installation folder as 'C:\Program Files (x86)\R 2.12, otherwise Essential for R could not be installed as it could not detect the version of R during its installation.