This is caused by an installation problem -- perhaps caused by a previous 3.5 beta not being uninstalled correctly. If I remember correctly, it's because the correct alink.dll is not next to al.exe. If you have a working machine, you could try copying it there. Otherwise, you'll have to uninstall 3.5, cleanse as much as you can, and reinstall.
There's probably steps somewhere on the web if you search for this message.
Dan