out of curiosity i checked my relatively recent windows 10 installation. i see 102 files ending in .com; 13 if filtered to unique files names. 12 in the windows folder, and 1 in a game folder. most of the windows folder ones are in System32m WinSXS, and SysWow64 subdirs, as well as some windows update subfolders. so it looks like mostly for win32 compatibility. i tried running system32/tree.com in powershell and it works fine