Welcome SJ Hair,
Thank you for reaching out to Microsoft Q&A forum.
I understand how frustrating it can be when purchasing Microsoft 365, you’re able to sign in to other Microsoft services, but Windows Security does not allow you to sign in and shows an error message saying something went wrong.
To help identify the fastest resolution, please confirm the following
- Are you signing in with a personal Microsoft account, or a work or school account?
- Does the issue occur when you open the Windows Security app itself, or only when accessing a specific section such as Account protection?
In the meantime, you can try the steps below to troubleshoot the issue:
Option 1: Make sure the required Windows Security services are running
- Press Windows key + R > type
services.msc> and press Enter - Ensure Security Center and Microsoft Defender Antivirus Service are set to Running
Option 2: Reset the Windows Security app
- Go to Settings > Apps > Installed apps
- Find Windows Security > select Advanced options > and click Reset
Option 3: Check for Windows updates again
- Go to Settings > Windows Update > select Check for updates
- Install any available updates and restart the device
Option 4: Sign out and sign back into your Microsoft account on the device
- Go to Settings > Accounts >Your info
- Sign out, restart the PC, and sign back in
I really hope that the information I gave above was helpful to you. Please feel free to reply below and let me know if you have further concern on this matter.
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