Registry Key '...' has value '1.7', but '1.6' is required. Java 1.7 is Installed and the Registry is Pointing to it

This happens when you somehow confused java itself. You are trying to run a java 6 VM where it found a JRE 7. It might show this problem even if you type in the command line just java or java -version in a misconfigured environment. The JAR is not the problem, except in the very unlikely case where the code in JAR is looking in the Windows Registry for that (which probably is not your case).

In my case, I had the java.exe, javaw.exe and javaws.exe from Java 6 in the Windows/System32 folder (don't know how it got to be there). The rest of the JDK and JRE where found in the PATH inside C:\Java\jdk_1.7.0\bin. Oops!

Just had the similar error when installing java 8 (jdk & jre) on a system already running Java 7.

Error: Registry key 'Software\JavaSoft\Java Runtime

Environment'\CurrentVersion' has value '1.8', but '1.7' is required.

Error: could not find java.dll Error: Could not find Java SE Runtime Environment.

My environment was set up correctly (Path & java_home correctly defined), but the problem arises from the way pre-8 Java installers worked, which is that they used to copy the three executables (java.exe, javaw.exe & javaws.exe) to the Windows system directory. These remain unless overwritten by a new pre-8 installation.

However the Java 8 installer instead creates symbolic links in a new directory, C:\ProgramData\Oracle\Java\javapath, pointing to the actual JRE 8 location.

This means that you'll actually run the old 7 exes but use the new 8 DLLs.

So, the solution is simply to delete the 3 Java exes, as above, from the windows system directory.

If you are running 32-bit Java on a 64-bit Windows, the exes would be in Windows\SysWOW64, otherwise in Windows\System32.

I've deleted java files at windows/system32 and I also have removed c:\ProgramData\Oracle\Java\javapath from the PATH variable, because there was 3 symlinks to java 1.8 files.

I had JDK 1.7 in the %JAVA_HOME% variable and java1.7/bin in the PATH.

PS1: My problem was between Java 1.7 and Java 1.8.

PS2: I can't add this as a comment to Victor's answer because I haven't enough points.