Ok, I've been able to use AIM without a problem since I installed Vista a number of weeks ago. Well all of a sudden I start up my computer today and try to open up AIM and it doesn't open. So then I go ahead and try it again, and it still doesn't open. Then I open up task manager and notice that aim.exe is running twice in process manager. So, basically the process will run but I can't get the program itself to open up. Reinstalling doesn't work. Uninstalling and installing doesn't work. The only thing that works is uninstall>delete remaining program files>manually delete all registry entries>restart>install>restart. It would then open up, but now everytime I restart my computer the problem returns. Anyone have any idea how to fix this? Its getting quite annoying.

What version do you have? I had the same problem when I upgraded. I was able to fix it with the beta version of AIM for Vista.
AIM® 6.1 Beta Test

Just accept the license agreement and the download should start automatically.

I'm using the latest 5.9 version. I can't stand 6.0. The thing is though, it worked fine for several weeks, it just stopped working a couple days ago.

Yeah I had the same problem -- Vista is screwy A patch is due out in June (or so they say). I hated 6.1 for quite a while too but it has grown on me and I feel awkward when I use older versions now :-p

Anyways, that solved my problem which sounds the same as yours.

Yeah, it worked. I guess I'll just have to live with it, unless someone can come up with a solution. 6.1 is just so overwhelming and confusing. They totally overdid it and made it unnecessarily complicated.