Hi,
I ran into this BitLocker issue for the first time and was really bothered with the decrypt/install/re-encrypt approach. As the boot and recovery partitions are not encrypted, I tried a different approach which worked fine. So there is a 4th option! Here it is:
- Manage your partitions manually:
- On windows, launch the partition manager tool (type “partition” in the search bar and it should show up).
- Resize your main Windows partition to leave enough empty space for your ubuntu install (e.g. 128Gb).
- Boot on Ubuntu installer disk.
- When prompted with the different install choices, choose the option to manually manage your partitions.
- Select the free space and create at least one partition (mount as “/”). If you do not know how many and which partitions to create, there are many posts on the subject already.
- Install your Ubuntu and enjoy.
The whole process took less than 5mn to setup on my machine. I bet the decrypt is much much longer and generates a lot of unnecessary writes (bad for SSDs). Sadly, the installer is not able to automatically manage an install alongside Windows when there is free space on the disk. It is like it detects BitLocker and redirects to the help message with the link to this page. Hence the only option for now is to manage the partitions manually, which may rebute some users…
I hope this helps others.