Looks like your IE settings have been hi-jacked...I have been suffering from this problem for some time but think I have it under control....Please go to my postings above (Baffled) and have a read...the site
http://doxdesk.com/parasite/lop.html has a very good write-up on the subject....Also worth downloading latest version of AdAware from Lavasoft....First move for me was to goto the startup menu and untick a suspect entry (mine was "OUOAYNL") which stopped the homepage entry (In IE click tools/internet options) from being changed....I still have a lot of work to do to clean out suspect .exe progs (which are not necessarily in the prog folder) and some other junk which I have not yet found....I can now start IE without all the advertising links....Wish you best of luck...