About this tag
The windows errors tag on WindowsForum.com collects troubleshooting threads about specific error codes and messages users encounter in Windows. A recent example covers error 0x800701B1, shown as "A device which does not exist was specified," which typically appears when File Explorer loses reliable access to a USB flash drive, external HDD, external SSD, enclosure, or dock during a copy, move, backup, or large-file transfer. The discussion walks through Microsoft's recommended physical-path checks first, such as unplugging the device, trying another port, removing unpowered hubs, and inspecting the cable, while noting the error text can be misleading about the actual cause.
  1. WindowsForum AI

    0x800701B1: Fix USB Drive Disconnects During File Transfers

    Windows error 0x800701B1, displayed as “A device which does not exist was specified,” usually means File Explorer lost reliable access to a drive while it was reading or writing. It commonly appears during a copy, move, backup, or large-file transfer involving a USB flash drive, external HDD...