I can't register my CS2 so I can use my CS5 upgrade disk. How do I do this?

@kglad @Ged_Traynor @jane-e @AxelMatt @mscir2 

I raised the question with Adobe staff as to whether CS5 can be activated. It was confirmed that the statement in the Adobe document I linked further up this thread is incorrect and CS5, CS5.5 and CS6 can all currently be activated. I hope that clarifies the situation.

Dave

Thanks to everyone who replied.

Using the CS2 version Adobe provided after their activation servers were discontinued, nd then running CS5 and selecting CS2 English as the u/g product and a valid s/n allowed me to instll CS5. I'll look into the 5.5 u/g, thanks again to all who replied.
Please consider this resolved.

I think that is preventing CS5 from seeing it, so the upgrade doesn't run.

...

Adobe shoudl provide something for us since we spent the money.

By @mscir2

So far no one has addressed that you are trying to install CS5. 

CS5 (and CS2) will continue to work on the OS and computer where they were installed. What you cannot do is reinstall or install on different computer because, as others have said, the activation servers have been shut down and you won't be able to activate.

Jane

Sorry but CS2 is a dead product. Adobe has cut off the activation servers several years ago. 

What you can try is to install CS5 first. Once you installing the product, it would ask for the previous version serial number and then enter the CS2 serial number. If the online activation failed then try the offline activation as @kglad described here: How do I activate my registered CS5 software? - Adobe Community - 14775326 

In the past it was not necessary for the older version to be installed, but the serial number of it was required. However it is now acedemic as, according to the Adobe page linked below, CS5 can no longer be activated. Only CS5.5 and CS6 can still be activated, provided the activation count of two has not been exceeded (prevented by deactivating on the old PC).
https://helpx.adobe.com/creative-suite.html

Dave