let a firewall and an anti-virus software run from boot-time run several anti-malware programs (there are many free ones, but not all are trustworthy) '''Malwarebyte''' http://www.malwarebytes.org/mbam.php '''Microsoft Safety Scanner''' http://www.microsoft.com/security/scanner/en-us/default.aspx '''Windows Defender''' http://windows.microsoft.com/en-us/windows/using-defender '''Spybot''' http://www.safer-networking.org/en/index.html '''Kasperky''' http://www.kaspersky.com/security-scan '''Rootkit scanner TDSS-Killer''' http://support.kaspersky.com/5350