This shows how to get terminal access on the GCW0 from Windows. This might be necessary to change file permissions in the internal storage.
1. Download and run KiTTY
(it's only an executable, just copy it somewhere).
2. Create and open a KiTTY Telnet session for the GCW0.
3. Now you can enter any sort of Unix (OpenDingux) commands, such as changing file permissions for a manually installed FBA version in this example.