Windows 10でUSBドライブが認識されない場合の対処法

2025年12月26日
Windows 10でUSBドライブが認識されない場合の対処法

という場合 USB drive not recognized Windows 10 problem appears, the first concern is usually your files. Windows may fail to show a USB drive in File Explorer even though ディスク管理 or Device Manager can still detect it. However, the correct fix depends on what Windows can see. A missing drive letter needs a different solution from a RAW partition, an unallocated USB, or a device that shows “No Media.”

This guide explains how to fix a USB drive not recognized Windows 10 issue without making data loss worse. You will learn when to check hardware, drivers, power settings, CHKDSK, or recover files first. If Windows still detects the USB but your files are inaccessible, Magic Data Recovery 実用的な USBデータ復旧 オプションがある。.

目次

USB Drive Not Recognized Windows 10: Identify the Problem First

Before trying random fixes, check where the USB appears.

目に見えるもの

考えられる原因

次にとるべき最善の行動

Missing from File Explorer but visible in Disk Management

ドライブ文字がない

ドライブ文字を割り当てる

RAWを表示

ファイルシステムの破損

まずファイルを復元する

Shows Unallocated

パーティションの紛失または破損

Recover data before creating a volume

Appears only in Device Manager

Driver/controller issue

Reinstall the device

「メディアなし」または 0 バイトと表示される

Hardware-level failure

Stop DIY repair

どこを探しても見つからない

Port, connection, or physical failure

Test another port and PC

A USB drive not recognized Windows 10 error is a symptom, not one failure. Therefore, match the fix to the device condition.

Why Is My USB Drive Not Recognized in Windows 10?

Common causes include a faulty port, missing drive letter, corrupted driver, USB power-saving settings, file system corruption, a lost partition, or failing flash hardware.

For example, a USB may disappear from File Explorer after unsafe removal while Disk Management still shows it as RAW. The files may still exist, but Windows can no longer read the file system. Therefore, protect important data before destructive fixes.

Before You Fix a USB Drive Not Recognized Windows 10 Issue

Use a recovery-first workflow: stop writing new data, check Disk Management, and recover important files before formatting RAW or 未割り当て space. Save recovered files to another physical drive.

Also, avoid repeated チェックディスク attempts on an unstable USB. Do not create a new volume over unallocated space if you need the old files. If the device shows 0 bytes, “No Media,” or constant disconnects, stop DIY repair.

In short, follow one rule whenever important files are involved: まずは回復、その次に修復.

Fix 1: Check the USB Port and Another Computer

First, start with the simplest possibility.

  1. Disconnect the USB drive.
  2. Connect it to another USB port.
  3. Avoid USB hubs during testing.
  4. If possible, try another Windows PC.

If the USB works elsewhere, the original PC likely has a port, driver, or power issue. However, if it fails on several computers, continue with Disk Management.

Fix 2: Check the USB in Disk Management

Next, open Disk Management. It is one of the best tools for diagnosing a USB drive not recognized Windows 10 issue because it can show devices that File Explorer hides.

  1. プレス Windows + X.
  2. 選択 ディスク管理.
  3. Find the USB by capacity.
  4. Check whether it appears as Healthy, RAW, Unallocated, or No Media.

If the partition is healthy but lacks a drive letter, continue to Fix 3. If it shows RAW or Unallocated, recover files first. Meanwhile, if it shows No Media, skip to the hardware section.

Fix 3: Assign a New Drive Letter

A missing or conflicting drive letter can make a healthy USB disappear from File Explorer.

  1. オープン ディスク管理.
  2. Right-click the USB partition.
  3. 選ぶ ドライブレターとパスの変更.
  4. クリック 追加 または 変更.
  5. Select an unused letter and click OK.

Then reopen File Explorer. If the drive appears, you solved the USB drive not recognized Windows 10 problem without changing its file system.

This method is especially useful when Disk Management shows a normal NTFS, FAT32, or exFAT partition but File Explorer does not list the device.

ドライブレターを追加して修正する-usbドライブを認識しない-Windows-10

Fix 4: Update or Reinstall the USB Driver

Sometimes Windows detects the hardware incorrectly because the USB driver or stored device configuration has become corrupted.

First, open デバイスマネージャー, expand ディスクドライブ または ユニバーサル・シリアル・バス・コントローラ, right-click the affected device, and choose ドライバーの更新.

If that fails, choose デバイスのアンインストール, disconnect the USB, restart Windows, and reconnect it. Windows should detect the device again with a fresh configuration.

重要なことだ、, ドライバーの更新 そして デバイスのアンインストール do different things. Therefore, reinstalling the device can help even when Windows reports that the best driver is already installed.

更新-USBドライバを修正-USBドライブを認識しない-Windows-10

Fix 5: Disable USB Power Saving

Power management can cause a USB to disconnect or fail to wake.

で Device Manager > Universal Serial Bus controllers, open USBルートハブ または Generic USB Hub properties and clear Allow the computer to turn off this device to save power.

Next, disable USB選択サスペンド under:

Control Panel > Power Options > Change advanced power settings > USB settings

Afterward, reconnect the drive and check whether the USB drive not recognized Windows 10 issue is resolved.

This solution is particularly useful when a USB works after startup but disappears after the PC wakes from sleep.

chkdsk-f

Fix 6: Scan for Hardware Changes

A temporary driver error may only require Windows to refresh connected hardware.

  1. オープン デバイスマネージャー.
  2. クリック アクション.
  3. 選択 ハードウェアの変更をスキャンする.
  4. Wait for the device list to refresh.

After the scan, check File Explorer and Disk Management again.

If the USB returns, Windows likely lost the device connection temporarily rather than suffering from file system damage.

Fix 7: Recover Data Before Repairing a RAW or Unallocated USB

If Disk Management detects the USB but shows RAW, Unallocated, a missing partition, or a format prompt, recover files before repair.

そこで Magic Data Recovery becomes useful. Instead of changing the damaged file system first, it scans a detectable storage device for recoverable files and lets you save them elsewhere.

Therefore, Magic Data Recovery fits situations where the main problem is inaccessible data rather than a simple Windows driver issue.

典型的なシナリオは以下の通り：

  • The USB appears as RAW.
  • Windows asks you to format the USB.
  • The original partition becomes Unallocated.
  • Files disappear after deletion or file system corruption.
  • Windows detects the drive, but folders no longer open normally.
Using Magic Data Recovery to recover files from USB drive not recognized

Fix 8: Run CHKDSK After Important Files Are Safe

CHKDSK can repair some file system errors, but use it only when Windows still assigns a drive letter, the USB remains stable, and important files are already backed up or recovered.

コマンドプロンプトを管理者として開き、実行する：

chkdsk X：/f

交換 X: を正しいドライブレターで入力してください。.

について /f option tells CHKDSK to repair detected file system errors. However, CHKDSK may change file system metadata while repairing the volume.

Therefore, avoid running it first on a RAW, severely corrupted, or unstable USB. If important files are still missing, recover them before using CHKDSK.

What If the USB Is Not Showing in Disk Management?

もし USB drive not recognized Windows 10 device does not appear in Disk Management, check Device Manager next.

If Device Manager detects it, reinstall the device, scan for hardware changes, and test another USB port.

However, if neither Disk Management nor Device Manager can see the USB on several computers, the failure may be physical. At that point, recovery software cannot scan storage that Windows cannot access.

Therefore, repeated formatting tools, CHKDSK commands, or driver changes are unlikely to help.

Tips to Prevent USB Recognition Problems

用途 ハードウェアの安全な取り外し before disconnecting a drive. In addition, avoid unplugging the USB during file transfers and keep another backup of important files.

You should also replace USB drives that frequently disconnect or report errors. Although these habits cannot prevent every USB drive not recognized Windows 10 error, they can reduce avoidable file system damage.

まとめ

A USB drive not recognized Windows 10 problem should be diagnosed before repair. First, check another port and computer. Next, use Disk Management to identify whether the USB is healthy, RAW, unallocated, or showing No Media. Drive-letter, driver, and power fixes can solve many logical problems.

However, if the USB shows RAW, Unallocated, or a format prompt, recover important data before CHKDSK, formatting, or partition creation.

Magic Data Recovery is recommended in this situation because it addresses the real priority: retrieving files before repair changes the storage structure. It is not a solution for physically dead flash memory. Instead, it is a practical USBドライブ復旧 option when Windows still detects the device but the files have become inaccessible.

If you are looking for a more efficient recovery solution before repairing the USB, try Magic Data Recovery.

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Windows 7/8/10/11およびWindows Serverをサポート

USBドライブが認識されない Windows 10 - FAQ

Why is my USB drive not recognized in Windows 10?

A USB drive not recognized Windows 10 issue can come from a faulty port, missing drive letter, corrupted driver, file system damage, lost partition, or hardware failure. First, check Disk Management and Device Manager. If Windows still detects the USB there, the problem is often logical or driver-related.

How do I fix a USB device not recognized error in Windows 10?

Reconnect the USB, test another port, and try another computer. Then check Disk Management. If necessary, assign a drive letter, reinstall the driver, disable USB power saving, and scan for hardware changes. Recover important data before formatting a RAW or unallocated drive.

USBがディスクの管理には表示されるのに、ファイル・エクスプローラには表示されないのはなぜですか？

The most common reason is a missing drive letter. In Disk Management, right-click the partition and choose Change Drive Letter and Paths. However, if the USB shows RAW or Unallocated, do not format or create a new volume before recovering important files.

What should I do if my USB shows RAW in Windows 10?

A RAW USB means Windows cannot recognize the current file system. Recover important files first. Afterward, format the USB with NTFS or exFAT and test it again. If the device disconnects repeatedly, stop using it and consider professional hardware diagnostics.

Why is my USB showing No Media or 0 bytes?

“No Media” or 0-byte capacity often points to a controller or flash-memory problem rather than a simple file system error. Try another port and computer first. If the same status remains, software recovery may not work because Windows cannot access the actual storage media.

Can CHKDSK fix an unrecognized USB drive?

CHKDSK can repair some file system errors when Windows still assigns the USB a drive letter and the device remains stable. However, it can modify file system metadata. Therefore, recover or back up important files first, especially if the USB is RAW or severely corrupted.

Can I recover files from a USB drive that Windows 10 does not recognize?

Yes, if Windows still detects the USB and can access the storage media. Recovery software may scan RAW, inaccessible, or lost partitions. However, if the drive shows No Media, 0 bytes, or is not detected on any computer, professional hardware recovery may be necessary.

検出されなかったフラッシュ・ドライブを修復するには？

ドライバの再インストールとディスクの管理から始める。ドライブが表示されてもアクセスできない場合は、フォーマットする前にデータを復元してください。.

バシリイは、この分野で約10年の実務経験を持つデータ復元のスペシャリストです。そのキャリアを通じて、彼は削除されたファイル、フォーマットされたドライブ、失われたパーティション、RAWファイルシステムを含む何千もの複雑なケースの解決に成功してきました。彼の専門知識は、16進エディタなどの専門ツールを使用した手動復元方法と、復元ソフトウェアを使用した高度な自動化ソリューションの両方をカバーしています。バシリの使命は、信頼できるデータ復元知識をITプロフェッショナルと一般ユーザーの双方が利用できるようにし、貴重なデジタル資産を保護できるようにすることです。.