Office Home & Student 2019 key is still valid?

Office Home & Student 2019 is a one-time purchase license that can be installed on only one PC or Mac at a time, but it can be transferred to a different computer owned by the same person under the transfer terms.

Key points based on the license terms:

• Office Home & Student 2019 can be installed on a single computer.
• It may be transferred to another computer that belongs to the same owner, but not more than once every 90 days (except in cases of hardware failure).
• When transferring to a new PC, Office must be removed from the old computer and no copies may be retained.
• After installing Office on the new PC, activation might need to be completed by phone if the online activation reports that the maximum number of activations has been reached.

So, if the license has been properly redeemed to a Microsoft account and is not blocked or otherwise invalid, it can still be used on a new PC as long as it is removed from the previous one and the transfer conditions are followed.

References:

• Transfer your Office license to another device or another person
• Activate Office after reinstalling or installing on a different device
• Download and install or reinstall Office 2021, Office 2019, or Office 2016
• Find your Office product key
• Using product keys with Microsoft 365