Launcher freezes at splash!

When I try to start the game, almost instantly when it gets to "Registering update wrapper" I get this wierd error message and the thing shuts down.

I've downloaded the HiRes version and even reinstalled, which takes forever on my 2mbit connection, but the problem persists.

My specs are:
Windows XP Pro sp3
Intel Pentium4 3.2GHz
2GB DDR RAM
GeForce 6600GT AGP 128MB

The error message is as follows:

Code:

---

An error has occurred.
Please contact Technical Support with the following information:

System.ArgumentException: The path is not of legal form.
  at System.IO.Path.nGetFullPathHelper(String path, Char[] invalidPathChars, Char[] whitespaceChars, Char directorySeparator, Char altDirectorySeparator, Char volumeSeparator, Boolean fullCheck, String& newPath)
  at System.IO.Path.FixupPath(String path)
  at System.IO.Path.GetDirectoryName(String path)
  at com.turbine.launcher.Launcher.RegisterPatchWrapper()
  at com.turbine.launcher.Launcher.Initialize()
  at com.turbine.launcher.Launcher.fadeInOrOut()
  at System.Windows.Forms.Control.InvokeMarshaledCallbacks()

---

Any ideas on what to do?


Images:
http://pici.se/pictures/lXMDneKgc.jpg
http://pici.se/pictures/NschKbaav.jpg

Ok so I tried installing the game with the exact same install-files on my brothers computer, and it works fine, so I'm assuming that the problem has something to do with my computer.. But the thing is that he has almost the same specs and everything... :/

Would be great if any actual mod or "support person" would take a look at this..