https://stackoverflow.com/questions/12748786/delete-files-or-folder-recursively-on-windows-cmd

Delete files or folder recursively on Windows CMD

 

You can use this in the bat script:

rd /s /q "c:\folder a"

Now, just change c:\folder a to your folder's location. Quotation is only needed when your folder name contains spaces.
 

 

The other answers didn't work for me, but this did:

del /s /q *.svn
rmdir /s /q *.svn

/q disables Yes/No prompting
/s means delete the file(s) from all subdirectories.