How make perfect usb for me which has back up of my required software most common drivers which are

Hi I m Ahmed, a fond of IT (COMPUTER) I know little bit know about computer that’s why they call me for repairing their computers. But one thing that irritate me that virus so I have to make a new back up. Virus either makes my USB useless or their computers.
Hence I want to know how to make a USB that has required software free of virus, back up of most common drivers.
I don’t install any antivirus on my pc because I believe that company never give their antivirus free of cost when they made it by investing money and free virus don’t perform well.
Please suggest me antivirus that full potential to block virus and other affecting programe give me or give me the link for it. Thanks in advance
I am waiting for your reply on [email protected]