ADOBE CS4 Ilustrator/InDesign and Windows 11

Two ideas that MAY work to install and/or run old programs in Windows 10 (and MAYBE Windows 11 ?)
-RIGHT click the program icon or EXE and select a compatibility mode in the pop up option window
-and/or select Run as Administrator to assign FULL Windows permissions
-also https://helpx.adobe.com/x-productkb/global/create-local-administrator-account-windows.html

In addition to the reply of @Test Screen Name:

Don't try to deinstall and reinstall your CS4 apps. The activation servers for CS2 - CS4 were cutoff several years ago. Youn can install your CS4 products, but you can't activate it. So they run in a trial mode for max. 30 days.

Adobe stopped supporting CS4 in 2013. So they did not change anything after that date (in fact, the final update was earlier). At this time Windows 8 had just been release. 

Now you hope this old, unchanged software will continue to work in the newer Windows 10 and now even Windows 11. But Microsoft change the systems, while Adobe do not change the app.

So for some people it fails. For others it keeps going. 

Yes, Adobe want you to now subscribe, this is their plan for getting income. But they didn't break CS4 to do it. (NB you can no longer install CS2, CS3, maybe CS4 because Adobe DID turn off the activation servers).