But a black screen without showing the laptop bios or logo is rarely a virus but a hardware failure.
Try this! http://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/
Can you see your files with this live boot CD?
Which CNET forum would I go to for help regarding a virus on a laptop using Vista?