Will changing from Entire computer backup mode to File level backup restart the backup?

[YewHang]

Currently, there is physical server which is backup via agent base and configured to Entire Computer backup mode. I want to exclude a folder. This can be achieved via changing the backup mode to File Level backup. Would by making the change cause the backup to restart, example it will do a full backup after the change. (exclude the folder I want to skip)

[Mildur]

Hi Yew

Yes, changing the backup mode to File will make a fullbackup necessary.
Veeam will process an active full backup after changing the backup mode.

For exclusion of a folder in a volume backup, you could try out the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\BackupRestore\FilesNotToSnapshot

More about this Key on Microsoft Docs