Often when you search a HTML help file (.chm extension) you find that the words you search for are highlighted and sometimes it can be too cluttered. A quick way to get the highlights removed is to click in the window part where the actual help shows up press F5 to Refresh (or right click and Refresh) the page just like in Internet Explorer. In Options there is also Search Highlight Off or Search Highlight On.
But in the AutoCAD 2007 Help file acad170.chm that is powered with AnswerWorks there is no way to see the search words highlighted. But there is a workaround. If you want to search in the users guide you can open that specific help file directly. In this case C:\Program Files\AutoCAD 2007\Help\acad_aug.chm. Autodesk Architectural Desktop 2007 Help file adt2007.chm for example is not updated to use AnswerWorks either.
An ADT 2007 and ABS 2007 help file related tip. You might have noticed that you cannot set favorites in the Help file in the 2007 products any more. Here is the workaround described. Open C:\Program Files\Autodesk Architectural Desktop 2007\Help\ADT.chm or ABS.chm directly from Explorer.