Photoshop CS4 Extended *Free* - download software for free -

The good : Veteran set of powerful imaging tools; streamlined user interface; more extensible and customizable; completely overhauled 3D engine in Extended version.

The bad: More of a memory hog than Photoshop CS3; print features and type engine still in dire need of an update.

Bottom line: If you work with 3D, Photoshop Extended is a must-have upgrade; ditto if you think you'd use more of Standard's tools if the interface were less opaque, if you need to upgrade other suite applications, or if you qualify for an academic discount. All things considered, while Adobe Photoshop CS4 makes some improvements over CS3, it might be worth skipping this generation and waiting for the next.

Review:

There's just enough that's better in the CS4 updates to Photoshop and Photoshop Extended--most notably, usability improvements for core features--that many people will find themselves sighing, biting the bullet, and upgrading. If you work with video or 3D, or want to update your Creative Suite to CS4 for other reasons, this is a no-brainer; for the rest of us, there's little you can do with CS4 that you couldn't do with CS3, and the latter seems a bit faster and more memory efficient in some respects.

source_cnet.com

download portable free here
Photoshop CS4 Portable.rar

Don't worry because even if it is portable feature, you can choose a single feature during installation (if you have had Photoshop CS3)