how to avoid to inserting pen drive into usb port of my pc?

Dear,

You could do this by putting policy in place.

If you need more information don't hesitate to ask.

Best Regards

Is this just for yourself or for lots of people.

If just for yourself you could try this free utility

http://technochat.in/2008/11/usb-cdrom-floppy-zip-drive-blocker-2/#more-374

You get get usb port locks
http://us.kensington.com/html/17084.html
http://www.everythingusb.com/usb_security_lock_13460.html

epoxy glue is pretty effective.
and so is Sanctuary:
http://www.lumension.com/data-protection/usb-security-protection.jsp?rpLangCode=1&rpMenuId=150824
we use it, and it's hard to beat.

you can do it via local policy, or to protect an entire site, similar to what DanCh99 suggested, you could look into Safend -- http://www.safend.com/11-en/Safend.aspx.  This what my company uses, and its very very effective, and not only USB ports, but all endpoint connections such as bluetooth, serial, wireless and firewire.  Handy feature of setting all CD/DVD burners to read-only too!  Everything gets logged, so you can prevent intellectual property theft too.

usb hd serial