Upgrade PSE 9

Yes if you have your original serial number, you can install PSE 2019 and get upgrade pricing from any previous version. But shop around as on-line stores such as Amazon and Costco etc. often have promotions, making the full product cheaper. With the full product you don’t need to worry about a previous serial number. If your computer meets the minimum requirements I suggest you download the software from the link below and use it as a free trial; presently available for 30 days. The interface is slightly different to PSE9 but most of the tools will be familiar. If you like it, there is no need to uninstall the trial. Simply licence with a serial number after purchase.

https://helpx.adobe.com/download-install/kb/photoshop-elements-downloads.html