I can't seem to get the silent switch to work...
This is the documentation for the installer:
"Nullsoft Scriptable Install System
The Nullsoft Scriptable Install System (NSIS) is another open source installation system. It was created by the WinAmp authors to distribute that application, but it is now a general-purpose system which anyone might use.
When an NSIS installer runs, it creates a little window which says verifying installer: N%, where N counts from 0 to 100. So you can recognize these installers by this behavior. (Actually the verification procedure is optional, but most installers have it enabled. As an alternative, you can run "strings" and grep for "NSIS").
NSIS installers recognize /S for silent installation, /NCRC to suppress the CRC (verification) step, and /D=dir to specify the "output directory", which is where the program will be installed. These options are case-sensitive, so be sure to type them in upper case.
Incidentally, all /S does is change the installer script's SilentInstall attribute from "normal" to "silent". What effect this has, exactly, depends on the person who wrote the script. If /S does not perform a silent install, consider submitting a bug report to the installer's creator."