There is no longer an official "free" version of ArcSoft PhotoStudio 4.0 provided by the manufacturer. Most "free download" links found today refer to one of the following:
Legacy versions are sometimes hosted on third-party sites like Softonic or Software Informer , but these are often limited trials or archived files that may not run on modern systems. arcsoft photostudio 4.0 free download
Originally, this version was often "free" because it came pre-installed with hardware, such as the Canon LiDE 20 scanner. There is no longer an official "free" version
For those who remember its peak, the software was valued for its simplicity and Photoshop-like layout without the steep learning curve. arcsoft photostudio 4.0 free download