Here you can download Design Manager installation files

Design Manager works with:
AutoCAD 2000-2018 (32 & 64 bit)
Inventor 2018 (64 bit) (64 bit does NOT work on Windows 8, Windows 10 is OK)

1/ Download Design Manager and unzip to a temporary folder then run DmMaster.Exe
2/ Release Codes are required to run these applications.
3/ The OLE Object setting for AutoCAD 2018 should be AutoCAD.Application if this does not work use AutoCAD.Application.22
4/ Application Caption setting for R18 is AutoCAD 2018
5/ For full functionality Design Manager requires the AutoCAD VBA enabler to be installed for the version of AutoCAD in use..
6/ If using Windows 7 or 10 we advise you to run Design Manager and AutoCAD/Inventor as Administrator, you can make this setting in the Windows properties for the application under the Compatibility tab. Also turn off UAC.
7/ If the database files are on a Windows server make sure users have EXPLICIT ‘Full Control’ rights over the folder
Membership of a group with rights is not sufficient due to an anomaly with Windows Server and .DBF files.

AutoCAD 2018 (32 & 64 bit), Inventor 2018 Version (64 bit)
Floating License manager installation
Client Server Application
Self running demo of Design Manager
AutoDesk Download page for VBA Enablers
Allows raw editing of Database files, unzip to a suitable folder and run DbfUtils.exe. Use with caution.
Check here for AutoCAD/Inventor compatibility and bug fixes
Main DesMan file only, UnZip to local DesMan folder (Usually c:\desman)