Oracle installed new version and hosed my Java environment

Question

Oracle installed a new version a day or two ago. Now I go to use it and I get:

C:\JavaTools>java -version
Error: opening registry key 'Software\JavaSoft\Java Runtime Environment'
Error: could not find java.dll
Error: Could not find Java SE Runtime Environment.

(I find 'Software\JavaSoft\Java Development Kit' in the registry, but no 'Java Runtime Environment'.)

No doubt something has been hosed in my path or registry or whatever, but I haven't a clue what. Any ideas?

(I did find this but it doesn't appear to address quite the same case. I didn't intentionally muck with any of the Java config, just said "OK" when Oracle asked to update my existing config.)

Cygwin finds these versions of java.exe -- I have no idea which one Oracle has supposedly been updating:

/cygdrive/c/Program Files/Java/jdk1.7.0_07/bin/java.exe
/cygdrive/c/Program Files/Java/jdk1.7.0_07/jre/bin/java.exe
/cygdrive/c/Program Files (x86)/Java/jre7/bin/java.exe
/cygdrive/c/Windows/System32/java.exe
/cygdrive/c/Windows/SysWOW64/java.exe

The only version of javac.exe I could find was at:

/cygdrive/c/Program Files/Java/jdk1.7.0_07/bin/javac.exe

%path% includes:

C:\"Program Files"\Java\jdk1.7.0_07\bin\

(I know I shouldn't have said "OK" when Oracle asked to update, but I was busy with something else and wanted to get it out of the way. That'll teach me!!)

Update: I finally just deleted and reloaded Java. One thing I was unsure of is whether I should touch the java.exe instances in Windows\System32 and Windows\SysWOW64 -- the old ones are still there, but don't seem to cause trouble. (I did delete the other paths, finally, after finding and killing the background job that was referencing some of he files.) Had to manually update %path% with the new version number. But Java seems to be working again.

Answer 1

Reinstall JDK and sets system variable. See link

https://www.java.com/en/download/help/path.xml