Solved Cant convert to MBR because of this (100MB EFI System Partition)

[TVeblen]

Glad you got it sorted. Good work!

 

[RvB Vakama]

1. If you have had a working Windows Installation, you could have simply run Partition Wizard installed in it. ( No need for creating a bootable PW pen drive)

2. The 128MB partition is the MSR partition on a GPT drive created by Windows. Windows Disk Management will always hide it from the users so that users cannot meddle with it. Partition Wizard and other partitioning software can see it.

interesting, good thing I don't need it for a mbr style disk, because I deleted it!