Your PC has trojan,TR/Crypt.XPACK
This Trojan allows for its author to control a computer by using Internet Relay Chat (IRC). The Trojan can update itself by checking for newer versions on the Internet.
Tracks installed security program, inactivate anti-virus and firewall applications
Crypt.XPACK.Gen logs and sends out operating system information, user names, keystrokes, passwords and other sensitive data
Tracks windows activity and system registry, generates popups that match browsing actions
Use system security leaks to infect pc with new trojan entries
Your PC is very likely compromised and there is no way to be sure your computer can ever again be trusted. Many experts in the security community believe that once infected with this type of Trojan, the best course of action would be a reformat and reinstall of the OS. Even though the infection has been identified and quarantined all financial,password and account numbers that were stored on this PC should be considered stolen.When Should I Format, How Should I Reinstall?
We will help you clean this PC but that would be a decision you have to make and there is no promise of future security without the format. Let us know how you wish to proceed.