You have earlier created a recovery drive for your Windows PC and at a certain time, your Windows installation is so damaged that it’s unable to load or repair ...
eSATA is another legacy port that’s disappeared ... the you get something like 1.8TiB for a 2TB drive. Alas, Windows labels this as 1.8TB, misleading the user. Other reasons you might not ...
A process called ‘partitioning’ is available with both Windows and MacOS. When you partition a hard drive, you’re basically splitting its internal storage space into different sections.