Hi, the reason PicoTorrent is 20MB installed is that we ship the PDB file in the installer. In the future, the PDB file will be optional. The actual executable is around 5,5MB. We ship the PDB file with the installer to help with issues now in the beginning - to print stack traces (with symbol names) if it crashes, etc.

The installer will receive a nice update with a user interface in the next version.

Thanks for the input! :)

Ninja Edit: I'll take a look at fixing whatever is making PicoTorrent not work in Sandboxie.