Hi Beecher, as an Independent Advisor, I'd be happy to help.
It sounds like a challenging situation. Here are some steps you can try to restore Internet Explorer mode on Microsoft Edge:
Re-enable IE Mode in Edge Settings: If the user has accidentally turned off the IE Mode in Edge, you can turn it back on by opening Edge, click on the three dots in the top-right corner, go to Settings > Default Browser, and then turn on "Allow sites to be reloaded in Internet Explorer mode".
Configure IE Mode using Group Policy: If you're using a version of Windows that supports Group Policy, you could use this to enable IE mode. Here's how:
Download the Microsoft Edge administrative template from the Microsoft website.
Extract the contents of the downloaded file.
Copy the .admx and .adml files to the PolicyDefinitions folder (usually located at C:\Windows\PolicyDefinitions).
Open the Local Group Policy Editor by pressing Windows key + R, type gpedit.msc, and then press Enter.
In the Group Policy Editor, go to "Local Computer Policy > Computer Configuration > Administrative Templates > Microsoft Edge".
Set the "Configure Internet Explorer integration" setting to "Internet Explorer mode".
Reinstall or Update Microsoft Edge: If Edge has been corrupted or if a particular update caused the issue, reinstalling or updating Edge might fix it. Since you mentioned the user can't redownload it, you could try updating it by opening Edge, clicking on the three dots in the top-right corner, and then choosing "Help and feedback > About Microsoft Edge". Edge will automatically check for updates.
Enable IE 11 on Windows 10: If the user is still on Windows 10, you can try enabling Internet Explorer 11. Open the Control Panel, go to "Programs > Programs and Features > Turn Windows features on or off", and then check the box for Internet Explorer 11. After restarting the computer, IE 11 should be available.
Remember, starting from Windows 11, Internet Explorer is officially retired, and Microsoft encourages users to switch to Edge with IE mode for legacy websites.
If none of these solutions work, you might want to consider reaching out to Microsoft support for further assistance.