I want to set my language to english but it detects os language which is japanese.
what should i do.(Both for creative cloud and Dreamweaver)
You should be able to select the language in the Creative Cloud Desktop App and have that language be the default when downloading programs through it.
I've never had to do it myself, but you should be able to uninstall any applications you've gotten with Japanese and reinstall after changing the setting to English in the CC Desktop App.
In the CC Desktop App, click the gear icon in the upper right and choose Preferences
You should get a screen with a General tab on the left and Creative Cloud on the Right
Click Creative Cloud on the right
Click Apps (far left tab)
Under App Language (first dropdown menu), choose the version of English you want
Click the left arrow icon in the upper right to exit Preferences
Click the Apps tab and download your software