You can have 2 active partitions in a system just fine, the boot order determines which is used. The trouble mufflore is having is that when 10 touches the nvme with 7 on it, the file system is left in a dirty state. Ie; https://www.sevenforums.com/perform...win-7-boot-dual-boot-win7-win10-computer.html However, if there is no fast startup / hibernate file on the nvme, it shouldn't be causing this. @Mufflore you might not be able to disable the nvme in device management, but you should be able to remove the nvme's drive letters. That would stop windows from mounting the volumes.