My server won't run on new java?

I upgraded my java version to 7 51 or something like that, anyway now that I have upgraded it, I can't run my servers; I just get this message in the command prompt: "C:\Users\Sean\Desktop\ServersNULLew folder>java -Xmx1024M -Xms1024M -jar minecraft_server.1.7.4.jar
'java' is not recognized as an internal or external command, operable program or batch file."

But before I upgraded I didn't get this message and it worked fine!

Please can someone tell me what I need to write or if I need to downgrade it? I would prefer not to degrade it though…

NOTE: I'm using the.jar version as the writing doesn't appear in the.exe file. This as recommended by someone on youtube and to uses the command code that I used, that DID WORK BEFORE.

This is when System Restore comes in handy…

Yes you will have to downgrade your version of Java… Only… That's not hard and very simple…

Just uninstall it then search for older versions of Java.

its that easy… Here goes a link for older version: http://www.oracle.com/...39210.html