If you read <a href=http://forums.techguy.org/showthread.php?s=&threadid=57588&highlight=sp.dll>this</a> thread and jump down to the post by HKEd you find your answer.
Basically do this,
Start>Run, key in msconfig and press enter. Click on the Startup tab. Locate the entry that reads "sp" and remove the checkmark next to it. Click on Apply and follow the prompts to restart. Once Windows has restarted do this,
Start>Find>Files, key in sp.dll and press enter. When it's found, right click on it and select Delete. Leave it in the RecycleBin for a few days.
Restart Windows and you should be fine.
Let us know what happens.