Hi LauChi, my name is Jose, a Windows user like you. I'll be glad to help you today.
To launch a scan using a command, first you need to open CMD as administrator. Then, please paste the following command:
cd C:\ProgramData\Microsoft\Windows Defender\Platform\4.18*
MpCmdRun -Scan -ScanType X
Replace de X letter with the number according with the scan type that you plan to run.
1: Quick scan
2: Full scan
You can get additional information using this link:
https://docs.microsoft.com/en-us/microsoft-365/...
Please let me know if you need any further assistance.