Booted from a USB windows 10 installer and I see four partitions
System
MSR
Primary
Recovery
Went to install on Partition 3 which is 235gb Primary and it says "Windows cannot be installed on this hard disk space, Bitlocker Drive encryption is enabled on the elected partition. Suspend (disable) bitlocker in control panel and restart the installation.
Obviously I cant do that as I cant login to windows.
I have the option to delete or format the partition but not tried that yet.
Any ideas?