Acrobat Reader 9

Hi,

Support for old products like Acrobat 9.x/11.x had been ended few years back. You can see the details on the below links regarding EOL:

https://helpx.adobe.com/acrobat/kb/end-support-acrobat-8-reader.html 

https://helpx.adobe.com/in/acrobat/kb/end-of-support-acrobat-xi-reader-xi.html 

You should use the latest product Adobe Acrobat Reader DC.

Regards,

Arvind

If I remember correctly (it's been a while...) only version 9.5 or higher was compatible with Windows 7.

Any reason you want to use such an ancient version of Reader, though? It's a big security risk, and you're missing out on a lot of useful features that were added later on. Why not use Reader DC, or even XI?

According to the system requirements page, Acrobat Reader 9 is supported on Windows 7.
https://helpx.adobe.com/au/reader/system-requirements-old-versions.html#AdobeReader9 

If it's not working, is there any reason you don't install a newer version of Acrobat Reader?