i am tring instaling adobe photoshop not installed in my pc only run in background

it's not clear what you've done, nor what you're seeing.  but the basics; install the cc desktop app from here https://creativecloud.adobe.com/apps/all/desktop?action=install&source=apps&productId=creative-cloud and use it to install your adobe subscription and trial programs. 

if you have trouble downloading the cc desktop app or you see an error message when trying to install, make sure you have a compatible os (https://helpx.adobe.com/creative-cloud/system-requirements.html), and use the alternative download links at page bottom here, https://helpx.adobe.com/in/download-install/kb/creative-cloud-desktop-app-download.html

What to do when you have a subscription (and an alternate download link)
https://community.adobe.com/t5/download-install-discussions/after-effects-set-up-wont-install/td-p/13554270