Java Error opening registry key

I get this error when I try to do anything with Java in command prompt:

Error opening registry key 'Software\JavaSoft\Java Runtime Environment.3'
Error: could not find Java.dll
Error: could not find Java 2 Runtime Environment

I did screw around with deleting Java directories and registry a few days ago. I restarted computer and java was still working fine, then i restarted it again today and now I get this error. I have tried uninstalling and reinstalling but that doesn't seem to work. I have the latest java JRE installed and the path set in the environment variables. Anyone have any clue how to fix this?

Make sure you remove any java.exe, javaw.exe and javaws.exe from your Windows\System32 folder and if you have an x64 system (Win 7 64 bits) also do the same under Windows\SysWOW64.

If you can't find them at these locations, try deleting them from C:\ProgramData\Oracle\Java\javapath.

You will find a folder named "Oracle" on ProgramData folder in your windows installed drive. Remove the folder. Hope it will work. In my case my install drive is C and my path is C:\ProgramData\Oracle

I had a similar problem. I had installed JDK7 update 1 but couldn't use it (probably because I found a JRE6 that I deleted after installing JDK7). Uninstalling JDK7 was impossible. The solution was to add the JRE registry entries by hand.

[HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment]
"CurrentVersion"="1.7"

[HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.7]
"JavaHome"="C:\\Program Files\\Java\\jre7"
"RuntimeLib"="C:\\Program Files\\Java\\jre7\\bin\\client\\jvm.dll"

[HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment\1.7.0_01]
"JavaHome"="C:\\Program Files\\Java\\jre7"
"RuntimeLib"="C:\\Program Files\\Java\\jre7\\bin\\client\\jvm.dll"

You'll have to adjust the above to your own directories and version.

If this doesn't help, there's still JavaRa https://singularlabs.com/software/javara/ .

Delete these 3 files present in your local at path C:\ProgramData\Oracle\Java\javapath

java.exe
javaw.exe
javaws.exe

This solved the issue for me :)