To install-

1.) Mount "Photoshop_12_LS1.dmg"
2.) Locate and click on the file "Install" on the image
3.) Select trial serial and install
4.) Quit photoshop if it opens after launch
5.) Open the 'Terminal' application and paste in the following:

sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /etc/hosts

6.) Enter your password and a text document will pop open
7.) Paste in the following between 127.0.0.1 localhost and 255.255.255.255 broadcasthost

127.0.0.1 activate.adobe.com
127.0.0.1 practivate.adobe.com
127.0.0.1 ereg.adobe.com
127.0.0.1 activate.wip3.adobe.com
127.0.0.1 wip3.adobe.com
127.0.0.1 3dns-3.adobe.com
127.0.0.1 3dns-2.adobe.com
127.0.0.1 adobe-dns.adobe.com
127.0.0.1 adobe-dns-2.adobe.com
127.0.0.1 adobe-dns-3.adobe.com
127.0.0.1 ereg.wip3.adobe.com
127.0.0.1 activate-sea.adobe.com
127.0.0.1 wwis-dubc1-vip60.adobe.com
127.0.0.1 activate-sjc0.adobe.com
127.0.0.1 hl2rcv.adobe.com

8.) Save the hosts document (command+s)
9.) Run the following in terminal to flush your cache:

sudo dscacheutil -flushcache

10.) Open Photoshop CS5 and click on the help menu and select "Deactivate…"
11.) Select "Deactivate Permanently" then done. Quit photoshop
12.) Reopen Photoshop and enter the serial

1325-0621-9125-0765-3648-0614
1330-1279-9841-9315-6622-5247
1330-1640-4705-3411-6165-4437
1330-1036-3594-4674-9744-3838
1330-1781-2022-6584-0111-4257

13.) Your done

no80dy