Studio Express installer can't find java

I'm installing Studio Express nt-x8664 on Windows 7 (64bit). In a command window, "java -version" returns "java version 1.7.0_25".
At the installer window with the text "Select Java Runtime Environment", I have tried every possible path for the "choose JRE destination folder" prompt, but the installer fails with the message "64bit Java Runtime Environment 1.6 or above is required. Please provide the required JRE path".
The java download page told me I was installing the 64-bit version.
Help, please.