What does Windows error code 118 (ERROR_INVALID_VERIFY_SWITCH) mean?

ERROR_INVALID_VERIFY_SWITCH

What ERROR_INVALID_VERIFY_SWITCH means

ERROR_INVALID_VERIFY_SWITCH is a Win32 system result whose documented message is: “The verify-on-write switch parameter value is not correct.” In practical troubleshooting, it belongs to older disk and file APIs that expose a verify-on-write switch and reject an unsupported or malformed switch value.

Typical causes

• a configuration parser passed a value other than the accepted on/off representation
• a structure layout mismatch moved unrelated bits into the verify field
• the caller used documentation for a different legacy API version

How to investigate the result

1. Capture the raw switch value immediately before the call
2. Confirm structure packing and field widths for the caller architecture
3. Reduce the request to the documented default and test again

Developer guidance

Represent the option as a validated boolean or enum and zero reserved fields. Reject invalid configuration before crossing into the operating-system API.

Administrator and support guidance

Review configuration imported from older releases, especially numeric flags. Resetting the option to its documented default is safer than guessing how an unknown value should map.

Example

A migrated configuration stores the value 2 for “automatic,” while the compatibility API accepts only 0 or 1, resulting in this result.

How it differs from related results

This code does not indicate that verification found bad data; it says the parameter controlling verify-on-write is itself invalid.

References

• Microsoft: System error codes 0–499