Just installed CS6 onto a new computer. I opened up Photoshop but a notice says I have to deactivate the serial number from another computer. I just did that, but I still can't get rid of the notice that pops up.

​@steveny29966189 

I’ve heard and read about such issue several times here in the forum.

User like to reinstall CS6 application on a new computer and deactivate the old installation correctly. But the reactivation on the new computer fails.

What you can try is a offline activation.

Steps for offline activation. Please follow them exactly one after the other:

1. Launch the product.
2. Disconnect the installed computer from the internet
3. At the Serial Number Validation screen, click Having Trouble Connecting To The Internet.
4. Click Offline Activation and click Generate a Response Code.
5. Write down the Request Code.
6. Switch to an online computer and navigate to www.adobe.com/go/getactivated.
7. Click Offline Activation.
8. Sign in with your Adobe ID.
9. Enter your Request code and (the product key?), then click Generate.
10. Write down the Response code.
11. Switch back to the offline computer.
12. Enter the Response Code and click Activate.