Windows Defender keeps finding the same threat

Repeated detection usually means Defender is finding another copy or the original source is recreating the file. Open Windows Security > Protection history, expand the newest event, and record the exact threat name, affected-item path, and remediation status. Choose Remove unless you are certain the file is safe, update security intelligence, restart, and run a full scan. Then run Microsoft Defender Antivirus offline scan from Scan options; it restarts into recovery to expose persistent malware. If the path is in Downloads, browser cache, an email attachment, compressed archive, temporary folder, or synchronized cloud folder, delete the source and copies, clear the related cache, and pause synchronization while rescanning. Do not add an exclusion merely to stop the alert. If a trusted file may be misidentified, submit it to Microsoft for malware analysis. If the same path returns after the offline scan, disconnect from networks and seek professional remediation.