There are many tools that enable PC scanning for viruses and many of them are free of charge.In the list below there are 16 online virus scanners.

• BitDefender Quick Scan
• ESET Online Scanner
• F-Secure Online Scanner
• Panda ActiveScan
• CA Threat Scanner
• Windows Live OneCare Safety Scanner
• Norton Security Scan
• Trend Micro HouseCall
• Kaspersky File Scanner
• avast! Online Scanner
• Virus Total
• Jotti Malware Scan
• Dr.Web Online Check
• VirusChief
• VirSCAN
• NoVirusThanks

Source: PC Pitstop