Uncompress recursively using 7-Zip from command line

Question

I'm attempting to uncompress several .gz files using 7-Zip from the command line. My files are in directories like so:

Desktop/copyto/1/
    file1.gz
    file2.gz
Desktop/copyto/2/
    file1.gz
    file2.gz
    file3.gz

I would like to recursively uncompress all the .gz files into each's orginal location and as well as deleting the remaining .gz files when they are done uncompressing.

I have tried the following command with no luck:

7z.exe x C:\Users\MYUSERNAME\Desktop\copyto\*\*.gz -r

I assumed that this would extract recursively. I get the error:

Processing archive: C:\Users\MYUSERNAME\Desktop\copyto\1\file1.gz
Can not open output file file1
Sub items Errors: 1

Any idea what's going on?