how to ensure no emClient dataloss when upgrading to Windows10

What is best way to migrate to a complete new windows10 installation,

where I need to reinstall emClient as well ?

Do you have a standard procedure for this ?

Is backing up de database file in AppData\Roaming\eM Client\ sufficient ?

thanks for letting me know

we do not have a standard procedure for this, but since Windows claims that your data will be untouched during the upgrade then making a backup through ‘File>Backup…’ should be enough.
A zip file will be created in your ‘…/Documents/eM Client’ folder that will have all your settings, setup and local data. You could make an emergency copy to an external hard drive, just to be safe.
Once you upgrade, if eM Client won’t load its database automatically, you can use ‘File>Restore…’ is the backup ZIP file is present in your Documents folder (if it’s not, copy it there from your external backup, but I believe one of the previous options should work just fine).