I would like to change Avast premium security for windows multi device to one PC. I don’t need more multi device. Do I have first unsubscribe the multi device?
Whilst I don’t use “Avast premium security for windows or multi device” so I can’t speak from personal experience.
Let your existing subscription get closer (not too close) to the renewal date - at which point you could look for a deal on a single user/system for Avast premium security.
But first I would suggest - Cancelling automatic renewal of the Avast subscription - See https://support.avast.com/en-en/article/35. This should ensure you don’t automatically get charged o renew the product.
See https://support.avast.com/en-ww/contact/sales_other_general#pc - 3. Contact us
Also see - Refunds, cancellations, billing, payment or license issues and click Next.
I need help with a different subscription or billing issue.
Depending on your location you can Phone or Email - I think the email option may be best as it establishes a support ticket with your email.
The Bold text is mine and possibly the best option for you to switch from multi user to singe user license and may well get a better deal.