For AVAST and AutoCAD 2011 solution is there https://forum.avast.com/index.php?topic=196987.msg1377226#msg1377226

Problem due to Avast Shell Extension Reg file for disable it: Код: [Выделить]

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions\Blocked]
“{472083B0-C522-11CF-8763-00608CC02F24}”=“”

On Windows 7 32 bit tested

On Windows XP and AVAST and AutoCAD 2011 this solution does not work

I have install ISO with AutoCAD 2011 and ISO Windows XP. You need ?