hi,
firstly make sure your windows vm is turned off.
look at the windows vm configuration in /etc/pve/qemu-server/100.conf and find the line with the disk, like scsi0 or ide0 or similar.
add this line to the config of vm 101
make sure you name it correctly, so if you already have scsi0 in vm 101, add it as scsi1
boot vm 101, you should be able to see the disk