Hello Reuvenf,
As per the description above, you are not able to convert a PDF file to Word on your new computer, is that correct?
The record shows that you are subscribed to Adobe ExportPDF service on your current Adobe ID, you can access the service through the URL https://cloud.acrobat.com/exportpdf with your Adobe ID and password on a browser like Chrome, or Firefox, or Safari.
You can also use the free desktop version of Adobe Reader DC to use the service of Adobe ExportPDF, just "sign-in" with your Adobe ID and password in Adobe Reader, to download Adobe Reader Adobe - Adobe Acrobat Reader DC Distribution
If Adobe Reader is already installed and while trying using the service and getting an error message, please sign out and sign back in Adobe Reader using your current Adobe ID and password and check for any pending updates of Adobe Reader from Help>check for updates.
For more troubleshooting, you may refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud Services).
Feel free to update this discussion for any further assistance.
Regards,
Anand Sri.