I thought I'd share my experiences on how to get my SB X-FI to work with Vanguard under Windows Vista. I won't get into much detail about why EAX doesn't work under Vista, but the effect is, that many people probably won't see a 'Generic Hardware' option in the sound settings of Vanguard.
Here is what I did to get hardware support and thus hardware sound acceleration ... which got me 10-12 fps btw
First you need to download Create ALchemy from here: http://preview.creativelabs.com/alch...%20ALchemy.zip
Now install Alchemy and open the Alchemy.ini file to add the following lines:
RegPath=HKEY_LOCAL_MACHINE\SOFTWARE\Sigil Games Online\Vanguard: Saga of Heroes\1.00.000\InstallPath
If Vista wont let you save the Alchemy.ini file in its location, you got to give yourself full access rights to the Alchemy folder.
Next step is a bit tricky since it involves editing the registry. I didn't find a better way since I dont have Vanguard installed in the 'program files' directory, but on another drive. This registry hack is probably the better solution anyhow. So go to Start and enter 'regedit'. Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Sigil Games Online\Vanguard: Saga of Heroes\1.00.000\, right click and create a new String called InstallPath, hit enter and type in the install path of your Vanguard installation, like f:\Games\Vanguard\
Now start Alchemy, select Vanguard on the left side and click transmute.
Enjoy hardware accelerated EAX effects under Vista
P.S: You can adjust the duration setting in your Vanguard\bin\dsound.ini file if you got cracking sound or something similar. I set the duration to 8 or 9 and it works perfectly for me.
P.P.S: If you just need EAX to work with Vanguard you can simply copy dsound.dll and dsound.ini from you Alchemy directory to your Vangaurd\bin folder and skip the alchemy.ini and registry part.