I have a bootable USB drive plugged into my PC and although it shows up in Disk Management, it doesn't show up in My Computer. Why does it have a weird symbol? It's the second drive in the list in Disk Management. Disk Management won't let me assign a drive letter, saying the list has to be refreshed, even though I just refreshed it.
From what I can see its a uefi partition which isnt normally visable and its what the pc boots from and should be on drive 0 and a few megs not the size it is.
Just try remove it before you boot and see if the system boots
There are a number of issues arising from your post so, like @Samuria, I advise you to check a few things and provide further information before doing anything.
By the way, you will often find the EFI system partition referred to as the ESP.
1 About it showing up in Disk management but not File explorer - I have never heard of Disk management assigning a drive letter to an EFI system partition and I have never heard of an EFI system partition being on a removeable drive so I imagine that your Disk management is similarly confused. My Disk management, by comparison, shows the Assign a drive letter selection & all the other right-click menu selections greyed out for the EFI system partition.
2 About its icon - Disk management uses different icons for fixed disks [such as your C & P drives] and removeable drives [such as your USB]. Your icon does not look weird to me.
3 About its size - The EFI system partition size does not seem, to me, to be a significant issue in its own right. Sizes vary. Mine is 500MB but I have always thought that its size was allocated quite arbitrarily by the computer maker & that 100MB or 200MB would have been sufficient. There are some explanations of EFI system partitions and other types of special partition in
Windows Partitions - TenForums
Understanding Disk Partitions - TechNet [MSDocs]
Clean Install [with lots about partitioning] - TenForums
4 If you remove that USB, does your computer boot correctly?
5 Why do you believe that USB is bootable?
6 How were the USB's contents written to it?
Denis
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