Reader DC automatically updating

Download the Adobe Customization Wizard DC, Install it, Run it as administrator if it doesn't work and disable automatic updates by first opening your package and then going into Online Features → Miscellaneous Features. Read the guide. It says like this:-

To disable online features, such as automatic updates and registration of software, select one or more check boxes in the Online Features list. To retain a feature, clear the check box.

Disable updates

Choosing Disable product updates results in the following:

• Removes the Check for Updates command from the Help menu
• Disables automatic updates so that a manual update is required
• Sets the following:

[HKLM\SOFTWARE\Policies\Adobe\<product name>\<version>\FeatureLockdown] "bUpdater"=dword:00000000 

https://www.adobe.com/devnet-docs/acrobatetk/tools/PrefRef/Windows/Updater-Win.html?zoom_highlight=updates#idkeyname_1_22988 - You may try this too although I haven't. Refer to the link.

Have a nice day,

Naruke Uzuha.