If you just need a 16-pad drum sampler with drag-and-drop simplicity, Sitala is a modern, free alternative. It doesn’t have Battery’s synthesis engine, but for sampling one-shots, it’s brilliant.
: If you cannot get Battery 3 to run, you can import its library kits into Battery 4 (version 4.2.1 or later) using the "Batch Resave" tool found in the Battery 4 software. native instruments battery 3 serial number