I know there have been a lot of posts on this subject, but I have a variety of machines and remain confused.

In Windows Vista, I think there was a service pack for their Ultimate Version that added BitLocker. It continued to be solely available in the Windows 7 Ultimate Version, but since Windows 8 has been available in the Professional Version. I have read the posts here and what I can find on the internet but I am having trouble understanding what the limitations are of BitLocker To Go are (e.g., Explanations like "BitLocker To Go-encrypted disks work identically on Windows 7, though with a legacy Explorer-based UI. On Windows XP, you will get a read-only Reader interface that lets you access the contents of the disk.')

Here are my questions:
  1. Since I have BitLocker To Go on my Windows 7 Ultimate and Windows 10 Professional machines, I am assuming it is best for compatibility and security to use the version of BitLocker To Go on the Windows 10 Professional version. Would that make sense or would that make this removable drive "read-only" for the Windows 7 machine (see #2)? Perhaps using the Windows 7 Ultimate version would be the most compatible one to use.
  2. Many internet documents indicate that BitLocker To Go creates a read only device for machines which do not have BitLocker. Other sites indicate that this is only true for Vista and XP machines. If I used BitLocker To Go to encrypt a removable drive on my Windows 10 Professional machine, would any of these computers be able to write to it?:
    • Windows 8 Home (no BitLocker)
    • Windows 7 Professional (no BitLocker)
    • Windows 7 Ultimate (older BitLocker)

I realize that there is some really basic concept that I am missing here, but if you understand this concept, could you please gently shove me in the right direction.