error 2604 no network connection when signing into excel

Question

I have had MS365 for 5 years now and now I can not access my excel or word account. in excel account it shows unlicensed and when I update license I get error 2604. I have internet and can sign into Microsoft account. I checked my Microsoft account and MS 365 is current, active and not due for 6 months. I tried almost all of the recommended fixes that i am comfortable with. the hotkey is not straight forward. tried credentials, online fix, reloading office, error and access to account unchanged

Answer 1

Follow these steps in order, focusing on activation, sign‑in, and connectivity, since the apps show as Unlicensed and error 2604 indicates a sign‑in/activation problem despite an active subscription.

1. Confirm the correct account is used in Office apps
   • In Excel or Word, go to File > Account.
   • Under User Information, sign out of all accounts.
   • Close Excel/Word.
   • Reopen Excel, go to File > Account, and select Sign in.
   • Sign in with the same Microsoft account that shows the active Microsoft 365 subscription on the web. If the wrong account is used, Office will show as unlicensed even if the subscription is valid.
2. Remove cached Office credentials
   • Close all Office apps.
   • Open Control Panel and select Credential Manager.
   • Select Windows Credentials.
   • Find any entries that contain MicrosoftOffice16 and select the arrow next to each, then select Remove.
   • Close Credential Manager.
   • Open Settings > Accounts > Access work or school.
   • If the account used to sign in to office.com is listed there but is not the same as the Windows sign‑in account, select it and choose Disconnect.
   • Restart the device and then open Excel/Word and try to activate again.
3. Clear Office identity information in the registry (Only if comfortable editing the registry.)
   • Close all Office apps.
   • Press Windows key, type regedit, and open Registry Editor.
   • Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity
   • Right‑click the Identities folder and select Delete.
   • Restart the device and try to activate Microsoft 365 again.
   • If the same unlicensed/activation issue persists, open Registry Editor again and go to the same key.
   • Right‑click Identity > New > DWORD (32‑bit) Value.
   • Name it NoDomainUser and set its value to 1.
   • Restart and try activation again.
4. Check antivirus, firewall, and proxy settings Activation requires access to Microsoft services even if general internet access works.
   • Ensure security software or firewall is not blocking:
     • C:\Windows\SystemApps\Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy\Microsoft.AAD.BrokerPlugin.exe
     • C:\Windows\System32\backgroundTaskHost.exe
   • Make sure the network allows access to https://login.microsoftonline.com.
   • If a proxy is used, temporarily turn it off:
     • In Settings > Network & Internet > Proxy, turn off any manual proxy and test again.
5. If wired connection shows “No Internet Access”
   • If using a wired LAN and it shows a yellow exclamation mark / “No Internet Access” while Wi‑Fi works, update the network card (NIC) driver from the manufacturer.
   • If that does not help, in Control Panel > Network and Sharing Center > Change adapter settings, right‑click the adapter > Properties > Configure > Advanced, set IPv4 Checksum Offload to Disable, select OK, and test again.
6. If none of the above resolves error 2604
   • Given that the subscription is active and standard fixes (repair, reinstall, credentials) have already been tried, the remaining cause may be a deeper Windows/Office sign‑in stack issue. In a similar case, the final resolution was a repair/reinstall of Windows 11, which preserved files but required reinstalling apps and restored Office sign‑in and activation.
   • Before taking that step, consider contacting Office support directly from the activation error screen or via the support options in the Microsoft 365 account portal.

---

References:

• Unlicensed Product and activation errors in Office
• Microsoft 365 Apps activation Unlicensed product error
• Connection issues when signing in after updating to Office 2016 build 16.0.7967 on Windows 10
• Can't sign in or activate Outlook and Microsoft 365 applications
• I can no longer login to office. I have a subscription - Microsoft Q&A
• When opening Word or Excel, getting a 'subscription canceled' message but I have renewed my Office subscription - Microsoft Q&A
• I have issue signing in to my microsoft office account. - Microsoft Q&A
• How to fix the issue with MS Office asking you to log in every time you open an Office app - Microsoft Q&A