Hi! Please make sure Windows Update has the latest patches, then open Windows Security > Virus & threat protection and run a Full scan, followed by a Microsoft Defender Offline scan (this restarts your PC and removes stubborn threats before Windows loads).
Afterward, check Protection history and remove/quarantine anything found. For a second opinion, run the Microsoft Safety Scanner (MSERT) download the 64-bit version, run a Full scan, and let it undo any malicious changes; if malware blocks the download, use another clean PC to put MSERT on a USB drive and run it from there.
If the system still behaves oddly, consider Reset this PC (keep files or remove everything).