It might not be blaster- make sure you have the latest virus definitions for your A-V program, and run a full system scan.

Give us the exact text of the error. Also have a read through the posts in this thread; a few causes of (and solutions to) svchost problems are discussed there.

Read through some of the posts in our Security forum for information on some of the recommended "malware" detection and removal tools. Try those programs and see if they find anything.

If the above suggestions don't give you the fix and you decide to post a HijackThis log, please do that in the Security forum, and be sure to include details of the troubleshooting steps you've taken up to that point.