There is no way how to change it when installed. You have to rainstall it and change language in the start of installation. There are so many different versions with diiferent languages, so you must have one with language you want.
p.s. Sorry for my bad English.
Adobe Photoshop is not multilingual. You must buy or contact support for localized version.
The language is set during installation if done via a legal copy. However, to change - Edit >Preferences - then select Country/region
See the related link below for official information from Adobe on how to change your language setting.
Go to Edit > Preferences > Interface then look at UI Text Options
Edit > Preferences > Interface look at UI Text Options section.
You must buy localized version of Photoshop. Adobe Photoshop officially does not ships as multilingual.
In www.microsoft.com/bih/
Portable version is not supported by Adobe, there isn't portable version available, you should think about using portable Photoshop.
C++
Each copy of Adobe Photoshop CS6 has its own password. If a person needs a password, it will be located on the back of the box that is purchased.
You have to exchange the disk via Adobe or to buy a new version. See related link for more details.
Adobe* made Adobe Photoshop.