Editing the registry in win 2000 .. HELP!!

I have been using some code to edit the registry and I am getting really deep into windows and it seems like windows either it being 2000 or just windows isnt letting me change certain keys..below are the location of the keys i am trying to alter..The wierd thing is I had this working perfect but now it doesnt work at all..I didnt change a thing and all the sudden it doesnt work..So I dont know what thats about but I think its some kind of security feature windows has..Does anyone have any STRONG registry code that the entry will ALWAYS go into the registry ...I seem to have this problem quit often when trying to change certain stuff..

It depends on your permissions settings. A way to aid this is to ONLY request permissions when opening the key that you absolutely need. If you specify KEY_ALL_ACCESS indiscriminately it will most likely fail.