Welcome to Seven Forums monats. May I suggest you post in the security section as isearch is harder to remove, and may just be an indicator of a larger problem. I'd suggest you follow Jacee's instructions on this post Help! Mocaflix virus
And start a new thread in security, including a link to your post in this thread ( http://www.sevenforums.com/software/232555-coreldrw-dll-error-code-998-a-2.html#post2328081
) System Security - Windows 7 Help Forums
Post the log file, and Jacee, or another security person will take it from there.