Since you created a file long enough to make your recording, there is probably some excess at the end. On my example in the picture below, I stopped recording after 215.24 seconds.
From that point to the end, there is about 25 seconds of silence. There is no reason to keep that, so let's cut it off. To do this, select "Delete After Current Postion" from the Edit menu:
When you have done this, the Position and Length numbers should be the same:
Now we need to trim the beginning of the file. Start by "rewinding" the file again (click on the button with the double-left arrow). Now you need to find the beginning of the music. Sound Recorder doesn't have a good way of doing this other than playing until the sound begins, so start playing the file. Watch the numbers in the "Position" as you listen so that you know where the sound begins. You will have to use old-fashioned gray matter on this one--remember the number you see when the music begins. You may want to listen two or three times to confirm the number. You don't have to be exact. Ignore the decimal. Just get the seconds correct. Now stop the music and click on the slider above the buttons. Carefully drag it left or right to about 1 second less than the number when the music began. Your screen might look something like this:
Now use the Edit menu to "Delete Before Current Postion." Good job! You have cropped your file.
Next step: Saving your wav file
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