Settings -> Interface -> Size Display format

Just installed the lastest version 3.0.1026.31
This option doesn't work for me, size is always displayed in Kb

It only applies to the size displayed in the Transfer Queue window. The browsers (Remote Browser, Local Browser) use the same format as Windows Explorer.

Regards,
Mat

AFAIK it's not possible to change size units in Windows Explorer...

Yes that's correct. But in SmartFTP's Remote Browser you can add an extra column to the view which displays the size in Bytes.

Regards,
Mat