I have CS5 and cant install it on my new computer

MX and Creative Suite are discontinued and unsupported.  Use at your own risk.  That's why Adobe support couldn't help you.

Creative Suite is no longer legally sold by any vendor, retailer or country.

Creative Cloud apps are certified to work with modern equipment and operating systems.  Membership includes free upgrades for as long as you remain a subscriber.
https://www.adobe.com/creativecloud/plans.html

=============
Beware of fake Adobe reps who may contact you privately offering to help, sell you software, or take control of your computer. It's a scam, run away!
=============
3 Easy Ways to Identify Genuine Adobe Staff
https://tinyurl.com/10791730

Hi @ellienor1510,

Sorry for your difficulty.  Macromedia MX 2004 activation servers were turned off many, many years ago. I don't know if this will work for you but try the special activation-free serial number towards the bottom of this link.

https://helpx.adobe.com/x-productkb/policy-pricing/macromedia-legacy-activation-error.html

Hope that helps.

If you have a valid activation number, CS5 should still activate without issue. The latest Mac OS won't allow Creative Suite programs to install or run, but Windows still works.

Are you getting a specific error when you try to activate?