How to fix error error-iopl-not-enabled in Windows 11

Solution Steps

1. 1 Press Windows key + R, type 'cmd', and press Ctrl+Shift+Enter to open Command Prompt as administrator. Type 'bcdedit /set increaseuserva 3072' and press Enter. This increases the user-mode virtual address space, which can help legacy programs run. Restart your PC.
2. 2 If the error occurs with a specific program, right-click its shortcut and select 'Properties'. Go to the 'Compatibility' tab and check 'Run this program as an administrator'. Also, check 'Run this program in compatibility mode for Windows XP (Service Pack 3)'. Click Apply and OK. This gives the program the privileges it needs.
3. 3 Press Windows key + I to open Settings, go to Privacy & security > Windows Security > App & browser control. Click 'Exploit protection settings'. Under 'Program settings', find the problematic program and edit its settings. Set 'Data Execution Prevention (DEP)' to 'Off' and 'Force randomization for images (Mandatory ASLR)' to 'Off'. This reduces security restrictions that might block IOPL operations.
4. 4 If the program is a DOS application, consider using DOSBox, a free emulator that provides a safe environment for old DOS programs. Download DOSBox from the official website, install it, and run your program inside it. This bypasses the IOPL restriction entirely.
5. 5 Press Windows key + R, type 'msconfig', and press Enter. Go to the 'Boot' tab, click 'Advanced options', and check 'Debug information' as 'Kernel'. Click OK and restart. This enables kernel debugging, which can help diagnose the issue, but it's not a permanent fix.