The '100% working' fix has one honest condition: the space must actually exist. Run this test before any fix — two minutes tells you whether you own a healthy drive with a messy map, or a fake that no command can cure.
Two customers walk in with the same sentence — 'my pen drive shows the wrong size' — and opposite problems. One needs five minutes with DiskPart. The other needs a refund. Applying the fix to the fake wastes an afternoon and can mask corruption until real data lands on it. So this page comes before the fix pages: one structural difference, two short tests, and a verdict you can act on.
A shrunk drive is a genuine drive with a redrawn map. Somewhere beside its small partition sits unallocated space — visible evidence that the rest of the drive exists and is simply unassigned. A fake drive has a small memory chip programmed to report a large size. There is no hidden remainder anywhere: the controller lies uniformly about the whole device, so Windows tools show the claimed capacity with no gap, no unallocated bar, nothing to reclaim. Everything in this test follows from that single difference.
Open Disk Management, or run diskpart and list disk, and read the total size of the device next to what Explorer shows.
History helps too: a drive that once genuinely worked at full size and shrank after bootable use is a partition case, essentially every time. Fakes were fake from the first day.
When the totals look fine but corruption says otherwise, only a write-and-verify test measures the truth. The long-standing free tool H2testw fills the drive's entire reported capacity with numbered test files, then reads every byte back. A genuine drive finishes clean. A fake reports its true usable capacity and shows errors beginning exactly where the real memory ends and the wrap-around overwriting begins. The test writes everywhere, so it erases — rescue any files first, and give it time on a large drive.
Shrunk: proceed with confidence — DiskPart clean or Disk Management, one full-size partition, done. The space exists; you are only redrawing the map. Fake: no format, clean, or 'capacity restore' tool can manufacture the missing memory — that is the honest meaning of '100% working applies to genuine drives'. Your real options are to return the drive and report the seller, or retire it. Technicians sometimes restrict a fake to its proven real size for throwaway use, but the wrap-around corruption gives no warning when you misjudge, so for anything that matters the correct action is to stop using it.
Watch the video's drive get its clean bill of health — then run the same two-minute check on yours.
▶️ Watch Full VideoEssentially no. Fakes are manufactured fake — they never held their claimed capacity, not even once. A drive with a genuine history of full-size work that shrank after being made bootable is a partition case, and the standard fix restores it.
Both are rounding the same bytes differently (decimal versus binary counting). The decimals do not matter for this test — the signal is structural: is there a large unallocated gap beside a small partition, or not?
It is extremely uncommon. Malware can damage file systems, but the everyday explanation for a shrunken report is leftover partitions from bootable tools — the pattern in the video. Confirm with the Disk Management picture before suspecting anything exotic.