I had a license，when I reinstall mycomputer with win10 system，I can not use PIX4Dmapper.Please help me to remove the device.
Hi @wwcad ,
Welcome to the Pix4D Community!
I have manually deactivated the device lenovo-PC from the license key associated with your account. There should now be a free seat on this license that you can use with another device.
Please note that you can deactivate your devices from your license management panel page.
For step by step instructions please see the article: How to remotely deactivate a device activated with your PIX4Dmapper license.
For further technical assistance, do not hesitate to contact us or to post on our Community.
Cheers,
Daniele
You’re welcome 
.
Happy processing.