The device has a bad block

What it means

The disk reported a sector it couldn’t read or write.

Why it matters

An early sign of a failing drive. Data loss may follow.

What to do

• Back up the machine now.
• Check SMART health with the vendor tool and plan to replace the disk.

Find it with PowerShell

Get-WinEvent -MaxEvents 20 -FilterHashtable @{
  LogName = 'System'; Id = 7
} | Select-Object TimeCreated, ProviderName, Message

Add -ComputerName SERVER to query another machine. Other event sources can reuse the same ID number, so check the ProviderName column.