|I am suspecting that you have a fake alert. what secuity setup do you have?|
Also, what program detected the blaster worm, please look carefully as it tries to have you clean the infection, there are multiple fake virus systems, the full name and maybe what it looks like will help.
Have you tried all these steps in this order?
the problem is that you need to deactivate what the worm is doing before it can be easily removed.