I use vista and I haven't had a problem chatting, I actually I use vista on two computers and it's not my favorite system but I don't think it's that bad. I had a bit of a problem installing plugins at first but I think I have figured it out now. When the pop up window comes up that shows the downloads that you have in order to actually install it you have to double click on the program that you want to install and follow the directions to get it installed. I have noticed that on somethings you have to manually download it, every time this has happened to me there has been a window come up that gives you the option to do it manually.
I am not a technological person so I hope that what I have explained makes sense, I am not very good at this kind of stuff or trying to explain it.