There is no legal "free" version of Photoshop CS1. The confusion usually stems from two historical events:
: The most powerful open-source alternative to Photoshop. It supports layers, advanced filters, and professional-grade photo manipulation. adobe photoshop cs1 free
If your goal with Photoshop CS1 was digital sketching and painting, Krita is vastly superior. Its brush engines, stabilizer features, and canvas controls blow 2003-era Photoshop out of the water. Conclusion: Leave the Past in the Past There is no legal "free" version of Photoshop CS1