I tried what you suggested but it didn't work. I went to C:\Users\USER NAME\AppData\Local\SecondLife and deleted the cache files and other icons in there, restarted my computer, and it still crashed during the VFS phase. So I tried deleting what was found in C:\Users\USER NAME\AppData\Roaming\SecondLife as well, but still the viewer keeps crashing.
Is there any other possible solution or should I try another viewer? I have no idea how to work Phoenix Viewer as I keep putting in my first/last user name in the respective fields and it keeps refusing to log me in (saying I put in the wrong name/password when I know it is indeed correct).