I apologize for the late reply to this question but I came across it by searching for "remove inventor 2020 items from Windows 10 context menu" and the 2 answers given, remove the items by un-installing Inventor (which seems a little harsh) and use MenuMaid (which is for Windows XP and is a little flaky in Windows 10) didn't help me.
I fixed the problem and wanted to post the fix here for anyone else who runs across this post.
TL;DR: Although the below methods work perfectly, and will indeed remove all unwanted context-menu entries, I have also successfully removed the offending Inventor entries with the free version of CCleaner here. (Open CCleaner > Tools > Startup > Context Menu tab > click 'Program' heading > find and disable 'InventorMenu' )
First, the items on the Windows 10 right-click menu items are of two types, 'shell' items and 'shellex' items. To keep this post shorter I won't go into what the differences are. It really doesn't matter in the end, anyway. [Edit: Okay,
'shell' items are always present, while 'shellex' items are 'dynamic' and show up in the context menu depending on what it is you're right-clicking on]
Different ways of dealing with this:
1) Edit the Windows Registry, which is not very safe and may not even clear up all the items you don't want in the context menu since not all Registry entries for dealing with context menu items are in the same place in the Registry.
2) Software utilities made by NirSoft (a trusted software developer) will get rid of either type:
Manage Shell items with ShellMenuView (https://www.nirsoft.net/utils/shmnview-x64.zip)
Manage Shellex items with ShellExView (https://www.nirsoft.net/utils/shexview-x64.zip)
Both utilities are 'Portable' meaning they don't install anything on your system, just unzip the downloaded files and double-click on the executable file inside to run it. Instead of trying to figure out which is the proper one to use, for 'shell' or 'shellex', I just run one, look for the items I want to remove and if I don't see them, run the other utility. Simple.
In addition, you can also modify the 'Open With' and 'Send To' items in the context menu.
1) 'Send To' is very simple as you only remove (or add if you wish) items from a special Windows folder called ...you guessed it ... 'SendTo'.
It's at C:\Users\[your username]\AppData\Roaming\Microsoft\Windows\SendTo. Delete any shortcuts in that folder that you don't want to appear in the right-click context menu in the 'Send To' section. (Tip: the easiest way to get to this folder is by typing shell:sendto into Windows 10 File Explorer's (formerly Windows Explorer) address bar and hit Enter)
2) 'Open With' is a little more difficult as it involves editing the Registry, although easier than 'shell' and shellex' items because 'Open With' items are all in one place in the Registry. The instructions are here: https://bit.ly/38g7Zld (Article at www.howtogeek.com)
That's how I got my right-click context menu back under control, not only with the items Inventor added but many others. When I right-click a folder I really don't want 'Open in Design Assistant' and 'Open in Inventor Read-only Mode 2020' very often, or more accurately, never.
I hope that helps someone.
