Command line can't find .java file from desktop

Hello,
I am not sure if this is the right place for this question, but I am having a problem running a Java program I wrote from the Windows 7 command prompt. I have saved the file as a .java extension on my desktop. Then, I open a command prompt and change to the desktop directory. Then I type in javac testnew.java and hit enter. Then I get an error that says,
"javac: Filenot found: Testnew.java
Usage: javac<options><source files>
but I know the file is there, I opened the command prompt right beside it on my desktop. Perhaps this is not the correct forum for this, but it says Programming forum, so I thought I would see if I could get some clarity on what is happening here....
Oh, and thanks in advance!!