Windows 10 Problem with Outlook 2021

It sounds like you're encountering a frustrating login issue with Outlook on your desktop, especially since your other devices (laptop and Android phone) are working just fine. Here are some steps you can try to resolve the problem:

1. Check Username and Password: Double-check the username and password you're entering. Sometimes, there could be a typo or the caps lock could be on inadvertently.

2. Reset Password: If you're sure the credentials are correct but still can't log in, it might be worth resetting your password. You can often do this through the web portal at outlook.com.

3. Clear Outlook Credentials:
- Go to the Control Panel on your PC.
- Select User Accounts > Credential Manager.
- Look for any stored credentials related to your email account and remove them. Then, try logging into Outlook again; it will prompt you to enter your credentials fresh.

4. Safe Mode: Start Outlook in Safe Mode to see if the problem lies with add-ins:
- Press Win + R to open the Run dialog.
- Type outlook.exe /safe and hit Enter.

5. Update Outlook: Make sure that your Outlook is updated to the latest version. Sometimes, bugs can remain unresolved in older versions, and updates often address these issues.

6. Repair Outlook:
- Go to Control Panel > Programs and Features.
- Find Microsoft Office in the list, select it, and choose Change.
- From there, you can opt to perform a quick repair.

7. Firewall/Antivirus Interference: Sometimes, security software can interfere with email clients. You mentioned having ESET Security enabled; it could be worth temporarily disabling it (if safe) to see if that resolves the issue.

8. Check Network Connection: Though your other devices are working, sometimes resetting your internet connection can resolve underlying issues.

9. Log in via Web: Since you have access on other devices, try logging into your account via the web browser (outlook.exchange365.com) on your desktop. If you experience issues there too, it may indicate a broader problem with your account.

If these steps don’t solve the issue, providing error messages or codes would help in troubleshooting further. Good luck, and let me know if you need more assistance!

I got on the web and logged into my account with no problem.
Network is fine, just slow.
Anti-virus is not interfering with outlook.
Repaired outlook and also opened in safe mode ending up setting up a new account by mistake but able to deal with it.
I cut and paste username and password and still cannot open outlook with outlook refusing my username and password.

It seems like you're navigating through quite a puzzle with your Outlook 2021 login issue. Since you've successfully logged in via the web and ruled out network problems and antivirus interference, let's dig a bit deeper into the specific problem.

Here are some further troubleshooting steps you can take:

1. Set Default Account: If you accidentally created a new account, ensure that your original account is set as the default within Outlook:
- Open Outlook and go to File > Account Settings > Account Settings.
- Under the Email tab, verify which account is marked as default. If it's not your original account, set it as default.

2. Delete and Re-add Account: Since you mentioned setting up a new account, it might help to remove the problematic account and add it back:
- Go to File > Account Settings > Account Settings.
- Select the account giving you trouble and choose Remove.
- Then, click New to add the account back, entering your email and password carefully.

3. Check Server Settings: Ensure that the incoming and outgoing server settings are correct for your Outlook configuration. Sometimes, if the settings do not match, login issues can occur:
- For Exchange accounts, server settings can usually be auto-configured, but check with your IT support or the documentation specific to your email provider.

4. Delete old Cached Credentials: Even though you checked the Credential Manager, make sure there are no leftover entries that could cause conflicts. Go back and ensure all previous credentials related to Outlook or Exchange have been removed.

5. Update Windows: Ensure that your Windows operating system is up to date. Occasionally, there are underlying OS issues that affect applications like Outlook, and updates can fix these.

6. Check for Conflicting Applications: If you're running any other applications that might interfere with authentication (like VPNs, proxy servers, etc.), consider disabling them temporarily to see if that resolves the problem.

7. Reinstall Outlook: As a last resort, if nothing else seems to work, consider uninstalling and then reinstalling Outlook. This can clear up any stubborn issues caused by corrupted files or settings.

Since Outlook seems to be quite stubborn this time around, keeping an eye on any updates from Microsoft regarding bug fixes for known issues could also help. If you still can’t resolve it, support forums or Microsoft support might offer more personalized assistance. Good luck, and don't hesitate to reach out for further help!