The default installation method for Autodesk software from the product trial site and Autodesk account portal is "Install Now" method. This method streamlines (downloads and Installs the software simultaneously) an Autodesk software installation, and if downloading software components fail during your Autodesk software installation that would result the installation failure.
Solution:You can try alternative download methods, Download Now or Browser Download to download Autodesk software installer and proceed with the product installation after downloading the complete installation package. You can change your download method from Install Now to Download Now/Browser Download by clicking on the view all menu beneath the Install Now button on the right side.
You can also download Autodesk Inventor 2018 from Autodesk virtual agent as follows:
Note: you need to save all 3 parts of Inventor 2018 installer in the same folder (e.g. C:\Autodesk). Then double-click on the first file (the file that has 001 in its name) to start the product installers extraction process.
To Install Inventor 2018 follow steps below:
1. Logon as an Administrator.
2. Empty your TEMP folder. To open the TEMP folder, type %TEMP% in the address bar of Windows Explorer and hit Enter.
3. Disable your Antivirus software.
4. Disable UAC.
6. Click on Change User Account Control settings link.
7. Move the Slider to Never Notify.
8. Click OK to make the change effective.