PIF files are perhaps madder. They're configuration files for MS-DOS programmes running under Windows. But you can rename an .exe to .pif and it'll still work a

PIF files are perhaps madder. They're configuration files for MS-DOS programmes running under Windows. But you can rename an .exe to .pif and it'll still work as an .exe as the same internal function to start an executable also handles PIF file parsing. But Windows Explorer considers PIF files "shortcuts", and so like .lnk files the file extension is always hidden even if visibility is requested. This included 64 bit Windows (at least for 10), which can't actually run MS-DOS programmes, and has no real reason to actually try and do anything for PIF files anyway.