First you need to download and install the Adobe Photoshop CS5 Extended Trial from the Adobe website. (You’re going to need a free account.) URL:
Then once the trial is installed, make sure Photoshop is closed and navigate to this directory:
Download the zip archive given below . Inside the archive there’s a file titled “hosts”. Extract this file to your desktop, then copy it to the above directory given in step 2 (driversetc). It should ask if you want to overwrite or replace the file. CLick “Yes” or “ok”.
If you have trouble overwriting, take ownership of your original “hosts” file then try replacing it again. OR Google this: “how to take ownership of a file”
Almost done. Open Photoshop. There will be a window asking for a serial number. Use one of these:
Now You Are Done!
If Any Problem With Trick, Then Feel Free To Ask.