Hi Guys,
this trick is not a new one, but it just need some sense of mind.
No need to use any software & hardware.

Lets Start from Basic.
How Virus Came Into Our PenDrive And What It Does?

The Virus first makes a file and then write its contents like what it need to initiate automatically.
It all happens through a file autorun.inf

So Here goes the trick to prevent the entrance of Virus into your PenDrive.

• Open a Notepad File.
• Copy & Paste this thing:

[autorun]
open = asknfdsafb.exe
icon = adfbkjasffdk.ico, 1

• Save the file as autorun.inf
• Now make this file Hidden & Write-Protected and paste it into your PenDrive

Note: Make a backup copy of this file. Do Not Format Your PenDrive. Incase, if formatted, paste the same file into PenDrive asap.