Likely causes:

• Port power issues; try a rear I/O port or a powered hub.
• Drive letter collision; assign a new letter in Disk Management.
• File system corruption; check with “chkdsk” or test on another PC.
• Missing chipset/USB drivers after a reinstall.
• ExFAT/NTFS compatibility issues on older systems.

Need help? Check here: /services/computer-maintenance/

What it might be (likely causes)

• Power and port quirks
  Front‑panel ports and unpowered hubs can brown‑out larger flash drives and portable HDDs. Rear motherboard ports usually deliver steadier power. For backup safety before experimenting: /posts/simple-data-backups-without-cloud/