How to check your removeable device for virus?

Maybe your anti-virus is not updated? If it is updated and still cannot detect try to replace your anti-virus program. If its still can't detect, maybe there is no virus in your usb device at all? But if you really sure that there is a virus in your usb and still cannot detect by your anti virus even if you replace it update it, the last thing i think is to reformat your device.

There is so many free Anti Virus that can handle it. Try to use AVG Free..

I suggest to use USB Disk security.. which is very cheap and also very effective when your USB is having virus which runs automatically.. you can ofcourse restrict it manually but may be among a million time you may forget once to press shift while inserting USB to prevent autorun, it can harm.. so I use USB disk security, which instantly alert if your USB having any autorun file or knows executable files.

If you have suspicious files that has virus, try using virus total. This is a way of checking for virus by the different anti virus. If your anti virus could no longer detect the virus and suspect that you computer or removable drive has virus, then try to uninstall your anti virus or say change it. The anti virus might no longer detect it perhaps because it is too many that it is already immuned. Safer way is that change your anti virus.

I am using Kaspersky antivirus. When I insert my pendrive which is infected, the AV programme automatically blocks the infected files. We can also go for full scan of only the pendrive, then also the infected file cannot be retrieved. Once the process is over you can transfer the remaining files onto your system. Then you can format the pendrive. This is the method I am adopting.

UPDATE your antivirus!