We need more details.
Windows Vista Home Edition, 32 Bits on a laptop with Core 2 Duo with an S3 video card and Realtek High Definition Audio.
When starting the Valkyrie client I get two popup errors even before the client opens, the second one happens when I close the first one.
The title of the error is ResetTheHotKey, and the content is "attempt to call a nil value". The second error has the same content as the first one. After closing the second error, the client starts, but it has no sound at all. It behaves normally but soundless till login screen, although it seems to lag a little longer than usual before opening the ESRB screen.
Since I have no server to log on I can't report anything further than this.