1; Uninstall all previous cs3/4 photoshop apps.
2; Turn off internet
3; Go to host file within the download, open with notepad and copy the text shown.
Goto start >All programs > Accessories > right click on notepad, click run as administrator, click continue when prompted, when notepad had opened click file > open > C:\Windows>System32>drivers>etc>hosts THEN deleted the text that appears and paste the copied text from the download host file > click save.
4; Restart and make sure hosts entries are saved (open it with notepad and look).
5; Install photoshop CS5 using serial 1330-1036-3594-4674-9744-3838
6; Copy the dll file from this folder and goto Start > All Programs > right click on Adobe photoshop CS5 > click on open file location > paste copied dll file into this folder, you will get a prompt, click on the 'move and replace' option.
7; Restart computer
Run CS5 and enjoy!
http://isohunt.com/torrent_details/184728933/photoshop?tab=summary