I need to run a full security scan on my computer but I don't have the advanced options to select it like I use to have

To run a full Microsoft Defender Antivirus scan even if the old “advanced options” view is missing, use one of these supported methods:

1. From the Windows Security app
   1. Open the Start menu and search for Windows Security.
   2. Select Windows Security.
   3. Select the Virus & threat protection tile.
   4. Select Scan options.
   5. Choose Full scan, then select Scan now.
   This is the current way to access full scan in the Windows Security app.
2. Using the built-in scan shortcuts (if the UI is acting up)
   You can trigger scans directly via the Defender protocol links:
   • Full scan: use the shortcut:
     windowsdefender://fullscan/
   • Quick scan: windowsdefender://quickscan/
   • Custom scan: windowsdefender://customscan/
3. Using PowerShell
   1. Open Windows PowerShell as an administrator.
   2. Run:

            Start-MpScan
      

   This starts a Defender scan from the command line.

If the Virus & threat protection page itself is missing or broken, first reopen the Windows Security app and ensure it loads correctly, then use either the Scan options path or PowerShell as above.

References:

• Virus and Threat Protection in the Windows Security App
• Microsoft Defender Antivirus in the Windows Security app
• Configure and run on-demand Microsoft Defender Antivirus scans
• About scheduled quick or full Microsoft Defender Antivirus scans
• Customize, initiate, and review the results of Microsoft Defender Antivirus scans and remediation
• Microsoft Defender Antivirus full scan considerations and best practices
• How to troubleshoot an error when you run the Microsoft Safety Scanner