I can't see iPad icon under device in my itune in my desktop computer

In preparation to upgrade my iPad software, i ave been advice to use the iTunes facility on my desktop

On connecting my iPad using the provided cable, iPad icon is not shown under device.

Pls advice

How can I backup my iPad.

Can I connect my iPad to my desktop computer with ineffective anti virus. Am not sure the anti virus is effective, recently I observed the hard drive is always busy executing one action on the other, which has drastically slow down it's response time, this started when a friend used hs flash drive on my computer, is it advice to connect my iPad to such, pls help.

Olusesi