Can't reinstall Photoshop to a new computer

CS5 came out in 2010.  Even with the original installation disks and available activations remaining, there's no guarantee that 15-year-old software will work on a modern computer.  They're too far apart.

MODERN OPTIONS:
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Photoshop Elements (3 year license, no subscription needed).
https://www.adobe.com/products/photoshop-elements.html

Creative Cloud Photography (12-month plan).
https://www.adobe.com/creativecloud/photography.html

Thanks for posting your question about your Creative Suite 5 license to this public discussion forum, Gary. If you purchased a retail license for Photoshop CS5 Extended, you can use the steps listed at https://adobe.ly/43zQyuv to request the software license and access to the installation files be transferred to your current account.

This process is only available for retail licenses; if you received an educational discount or were provided an educational license for Photoshop CS5 Extended, Gary, then the software is non-transferable. You'll need to gain access to the e-mail access to which the software was registered. Once you have access, then you can complete the steps listed at https://adobe.ly/41TLTlW to request a password reset for your Adobe account. ^JW

then you won't be able to download.