The aptly-named Paint.Net PSD Plugin is one of those pieces of software which pretty much spells it all out right in the name. It’s a plugin…for Paint.Net…(wait for it)…which lets you open files saved in Photoshop’s PSD format.
Download the zip archive, dump the included PhotoShop.dll file into your Paint.Net FileTypes folder (usually c:\program files\Paint.Net\FileTypes), and you’re ready to rock. Pretty well anything in the PSD for which Paint.Net has an implementation will load just fine. Saving is another story, so you’d best stick to Paint.Net’s native .PDN file when you’re done working.
If you don’t have Photoshop, the plugin is a handy for looking at PSDs your friends might send you to look at. It’s also a nice way to transition yourself to a free alternative if you no longer require Photoshop.
Visit: Paint.Net PSD Plugin