To prevent the shut down, do the following (steps 3 - 6 in under 60 seconds):
1. Disconnect the computer from the network/Internet connection. (Disconnect the cable if necessary.)
2. Restart the computer.
3. As soon as Windows opens and you see the Windows desktop, click Start > Run.
4. Type:
cmd
and press Enter.
5. Type:
shutdown -i
and press Enter.
6. In the Remote Shutdown Dialog that opens, do the following:
1. Click Add, type your computer name into the Add Computers dialog box, and then click OK.
2. In the "Display warning for" field, type 9999.
3. Type the following text in the Comment box:
Delay Lsass.exe shutdown.
4. Click OK.
7. Reconnect the network/Internet connection.
8. Connect to the Internet, and get the patch.
http://www.microsoft.com/technet/security/bulletin/MS04-011.mspx
then run ADAWARE or any other virus scanner to remove the virus.