What is Win32 Error 0x00000073 (ERROR_INVALID_CATEGORY) and How Can I Fix It?

  • Symbolic Constant: ERROR_INVALID_CATEGORY
  • Decimal Value: 115
  • Hexadecimal Value: 0x00000073
  • Explanation:
    The specified category does not exist. This error typically arises when a control function is called on a device with an unsupported or undefined category.

🔸 Root Causes

  • Passing an unsupported control category to DeviceIoControl or similar APIs.
  • Using obsolete or incorrect control codes on legacy hardware drivers.
  • Mismatched IOCTL definitions between caller and driver.
  • Calling a driver with a category it does not implement.

🔸 Step-by-step Fixes

✅ 1. Validate IOCTL Category

Ensure that the control code passed to DeviceIoControl is supported by the device or driver.

✅ 2. Match Driver and Control Code

Ensure user-mode code aligns with kernel-mode driver expectations.

✅ 3. Update or Reinstall Driver

If the category was once supported, the driver might be outdated or corrupt.

✅ 4. Use Properly Defined Control Codes

Define IOCTLs using correct CTL_CODE macros:

c

#define IOCTL_MY_CATEGORY CTL_CODE(FILE_DEVICE_UNKNOWN, 0x800, METHOD_BUFFERED, FILE_ANY_ACCESS)

🔸 Authoritative References

🔸 Technical Metadata

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