troubleshooing of the office2007 and adobe help system

I have long suffered from a help system malfunction. Both my adobe 1.1 help viewer and office 2007 help viewer can not show its content normally. Today, I finally solved the problem.

Origially, I have rooted the problem as a result of turning off kis for 1month. But, it seems I'm wrong. I have once configured the "set program access and default" to enable firefox as the default browser. This proved to be the sin of the whole thing. Today, I set the default browser back to IE and everything return to normal.

Firefox is so powerful a brower that I still want it as my default choice. I tried, and find that possible, too. You need only to set firefox as the default browser at firefox's option dialogue.

I guess the "set program access and default" will associate many file protocol including those that it shouldn't have to firefox. But, both adobe help and office help system are only designed based on ie engine, so with the wrong protocal association the help viewer can't show its content normally.
It's good that I can now use my help system. Only now did I realize how convinient the help systems are.

I have long tried to find a way to solve the problem,but failed. Today, I finally solve it. I think someone(Of course those who often hacks their systems) may also met this problem, hope this post can help you.