I can use Yahoo messenger to IM but it will not let me chat or use none of the extras such as IMviroments.Went to Yahoo messenger help and wanted me to re-download it but my computer will not let me.

Sounds like you have an old version of Yahoo Messenger.

Download the newest version of YM and see if that corrects the problem.

AS the good Captain has said maybe time to d/l the most recent version.
Just to add, its best if you remove the older version, via add/remove programs, first.

Thanks I'll try this. Have a lovely day.