Every time I start an internet session, I am told in a dialogue box that a program has tried to corrupt my search engine preferences.  Closing that box brings me to the page where I can set up those preferences, including a box which can be checked "Don't allow changes."  Selecting this makes no difference.

The PC is a new build, ASUS Mainboard, AMD Phenom Processor Quad Core, 3.5, 4 gig memory, 1 gig video mem, 500 gig SATA HD (Hitachi) Win 7 Home Premium 64 bit.

Open Office installed, Microsoft Publisher, and Nero Multimedia Suite 10.  It is the latter that I suspect, because during the install, I rejected the option of ASK as a search engine and the NERO toolbar.  Any thoughts?