Partitions show on Windows 10 machines but not on Windows 7 machines

[epck80]

I have made a USB drive with 4 partitions on it and on any Windows 10 machine, all partitions show with no issues. When I plug into any Windows 7 machine, three of the four partitions do not show in Windows explorer. When I look in disk management, the three that I am looking for show up as logical drives at the size that I have designated. Can anyone tell me what is happening and how to fix it please? It is quite annoying.

 

[jojesa]

You might need to assign drive letters to each partition on Disk Management.

 

[Colif]

Can you show us a screen shot in disk management (win 10) - upload to an image sharing web site and share a link here

Is it a USB flash drive or hdd? If its a hdd, its possible its been formatted as GPT and Win 7 (if its 32bit) cannot access GPT drives and sees all 4 partitions as 1 big partition to avoid you overwriting any info