If you have the purchased serial number, you can use download of the program from
3. If you purchased download from Adobe, go to the Adobe web site, sign in with Adobe ID and Password, in Search Field type in My Orders. Then navigate to My Orders until you get to your specific order for 9. The download files should be there.
I would start with "2". Often it is best to download and install with antivirus and firewall(s) disabled.
If any questions or need clarification, please do not hesitate to ask.