If you connected the PC to the Internet without having first
installed the KB824146 Hotfix, without having first installed an
antivirus application with current virus definition files, and before
enabling a firewall, you're very likely to get infected from any of
the thousands of PCs on the Internet that are constantly broadcasting
the Blaster and/or Welchia worms. It only takes a few seconds of
exposure.
To stay on-line long enough to get the necessary updates, patches,
and removal tools, click Start > Run, and enter "shutdown -a" when the
next RPC countdown begins. This will abort the shut down. Also, make
sure you've enabled a firewall before starting, to preclude any more
intrusions while getting the updates/patches/tools.