The PIN code is not entered on the PC and therefore cannot be intercepted.
PC's of corporate users are more and more often targeted by cybercriminals. Research reveals corporate computers are often infected with viruses and other malicious software. With malware such as keyloggers, cybercriminals are able to intercept keystrokes on your keyboard. Therefore, typing a card's PIN code on your computer's keyboard is considered unsafe, and shouldn't be done under any circumstance.
The Isabel card reader has a numeric keypad where you enter your PIN directly.