By default RivaTuner limits its own process access privileges to protect itself from unsafely designed memory scanners like PunkBuster anticheat system, which can cause unpredictable results due to unauthorized access to hardware I/O ports mapped memory ranges. Set this value to 0 disable this protection.

[b]Tip:[/b]

This protection may cause some primitive anticheat and antivirus systems to sound alarm. Disable it if you're not affected by PunkBuster's memory scanning issues.