1) Install Adobe After Effects CS3 Professional by running "Setup.exe".
When you are asked for a serial, use one of the following:
1023-1786-7233-7189-9068-1192
1023-1586-7233-7189-9068-1116
1023-1086-7233-7189-9068-1164

2) Once installation is complete , delete 
C:\Program Files\Common Files\Adobe\Adobe PCD\cache\cache.db

3) Then run Adobe After Effects CS3. Click Accept to continue, 
then enter your serial that used to install. 
BEFORE clicking next, you'll notice that you have a NEW cache.db 
file in C:\Program Files\Common Files\Adobe\Adobe PCD\cache

4) Right click the new "cache.db" file, go to properties and make it 
 READ ONLY, and then click next after entering your key.

5) When the Activation options screen shows up, select to do so 
OVER THE TELEPHONE, the press ok

6) Now copy and paste the "Activation Number" given into the keygen, 
called "Adobe After Effects CS3 Keygen" it is located within
the "keygen" folder, and press the "Activate" button

7) Next,copy the authorization code generated into the Phone 
Activation screen, and press "Activate", then press "Done"

8) After you get to the register software screen,
click "Register Later"

9) Now it should be working, technically speaking that is, but 
you're not done yet. The register screen should have popped up again.
This time, remove the check for "Read Only" from that new cache.db 
file and select "Never Register" from the registration screen

6) Now, as soon as you click continue, make the cache.db file 
read only again, and LEAVE IT THAT WAY to prevent a possible
 reoccurrence or Adobe trying to send the patch through again 
disguised as an "update".

Remember that if you need to reinstall the serials of any CS3 product
 which was working prior to the creation since you have created a new 
cache.db file you must temporarily uncheck the ?read only? properties
 box for the cache.db.

Then after inserting the serials and reactivating them close the 
program and then recheck the box.