USB stick won't show up in File Explorer so I can't format it

if it shows up but won't format because it's write protected, check the side of the stick for a tiny lock switch first. some have one. if not, in diskpart after select disk N, run attributes disk clear readonly and try again.

check Disk Management (right-click Start > Disk Management). the stick very often shows up there, it just has no drive letter, or the partition is in a format Windows can't read. - if it shows with a partition but no letter: right-click it > Change Drive Letter and Paths > Add - if it shows as unallocated: right-click > New Simple Volume and go through the wizard, that formats it - if right-click won't let you do anything, diskpart can wipe it (list disk, select disk N, clean, then format in Disk Management). be very sure you've got the right disk number, going by size, or you'll wipe the wrong drive if it isn't in Disk Management at all, try another port and another PC. still nothing means the stick is dead.