I have Vista as well and I thought at first that JMStudio was just another form of Sun Java package which most systems seem to have and need, even if we don't specifically know why.
But I don't have JMStudio on my system, and like you I searched Google and can find nothing really definite about it. Can you tell us more?
You say you just got this program on your computer. How did you find it, and where are the files located? Any clues in the program's folders?
Since AT&T say this is not part of their software it is possible that was just a coincidence,and that this is a component of some sort downloaded as part of something else, eg a browser plugin or some other software. Maybe you downloaded a new media player or something? Any other changes to your system for the date this JMStudio's folder appeared?
I just got a new Java program on my computer from Sun Microsystems called JMStudio. It appeared about the same time I set up access to my new "Unified Messaging" voicemail from AT&T. After looking at it, I couldn't figure out what it is for, what I needed for or what to do with it. When I contacted AT&T about it I was told it's not from them and not related to my new voice mailbox. Consequently, I Googled it and found that it has something to do with audio and viodeo programs, but I don't write any programs. So, I would appreciate it if someone could tell me if I need this program and, if so, what for?
In case it matter, I am running Vista 64bit on an HP Pavilion Model a6554f. I don't know about the sound card, etc.