There are a few points...
Firstly, if you are just starting to learn scripting, then you are advised to use Python, rather than Scheme.
In the windows command line you cannot use single quotes, so you have to "escape" the double-quotes round the file name:
gimp-2.8.exe -b "(mytest \"1111.png\")"
Which leads onto why F:\w\1111.png doesn't work - it is treating the backslahes as special characters and they would need to be "escaped" on their own: F:\\w\\1111.png, although windows should also work using the Unix directory separator F:/w/1111.png
Kevin