You cannot download the installer from Molecular Devices for version 5.4 (they no longer host it). You must use the original CD or find a trusted backup from your lab archives.
: While official SoftMax Pro 5 download pages exist for existing customers, a valid version-specific serial number is required to activate and use the software. Status of SoftMax Pro 5.4 softmax pro 5.4 free download
SoftMax Pro version 5. Consequently, there is no official "free" version of the full software. Molecular Devices Molecular Devices SoftMax Pro For Sale - LabX You cannot download the installer from Molecular Devices