Installing cs4 on another computer

If you're on Windows 10, you might try installing in compatibility mode. 

Log-in to your Adobe Account at https://acccount.adobe.com.    If you originally ordered digital downloads, you might see a link for CS4 in your portal.  If not, you will have to contact Adobe Customer care via online chat.  They will ask for your serial number or a proof of purchase so have that handy. 

Unfortunately, none of this will work for academic or volume license editions.

1. Catalilna, Apple's latest OS due out this fall, cannot support 32-bit apps.   The CS4 installers won't work.
2. If you want to keep using legacy software, you need an older operatnig system on a virtual machine or 2nd computer to support it.
3. Failing that, you must budget for new software. 

See Creative Cloud system requirements +  requirements for all other apps you intend to use.

https://helpx.adobe.com/creative-cloud/system-requirements.html

Well more than likely CS4 won't run on a new computer OS. Might on Windows10 but probably not on Mac OS X.