Scan computer for viruses Updated April 03, 2021 23:56 To perform a manual Antivirus scan on your PC open ZoneAlarm and click Scan in the upper right corner. Select the type of scan you wish to perform. Quick ScanFastest. Scans only Windows folders, Startup folders, and folders linked to startup items, which are common places for hackers to place viruses. (Programs in these folders can run automatically without permission, which creates the most risk.) Full ScanVery thorough. Scans all files and folders, and scans for rootkits. Skips Archive files. Full Scan with Archive filesVery thorough. Scans all files and folders, and scans for rootkits. Scans contents of zip files. Can take many hours to perform.