MarkBeauchene
I have a Lexicon Alpha for input, too bad it doesn't have output too.

 
Sure it does, "2x2":

• 2 x TRS line inputs 
• 2 x TRS & RCA line outs. 

That's your solution: connect your monitoring to the Alpha's outputs, set driver mode to ASIO, select the alpha's drivers, and make sure the Playback and Record timing master are set to the Alpha's I/O.
 
 

Your realtek soundcard is for playback of different formats of digital audio a typical computer will deal with.  8 bit windows sounds, mp3s, CDs, various formats of web video.  It does a good job for those.  An audio/midi interface is for delivering high quality sound, both in and out under strict timing.  Many times, video and multi-format sounds will mess them up.  It is like taking a 60's muscle car to your kid's school through multiple school zones every frigging day. For home studios and simplicity, RME is probably the best interface.  Good hardware, great drivers.  But expensive.  Farther down the list is Focusrite, who make everything from $100+ on up interfaces, and most people have no problems.  Roland/Cakewalk interfaces are popular w/ SONAR users for obvious reasons, tho that may be changing.  If I was picking up a cheap interface today I'd probably go w/ Focusrite just from word of mouth here and other places.  If I was picking a more expensive interface I'd probably go w/ their Forte unit ($500), since I don't have need for too many inputs.
 
Also let us know your budget.  You can go as low as $100 and get a decent 2 X 2 interface.  More money doesn't get you better drivers, usually, or converters, but more of them.  A 2 X 4 is nice to have, if you route an output to hardware and still monitor.  Also give an idea of how you make music - do you do singer/songwriter stuff, need to record a band, or mainly doing midi work.  That will make a difference in a interface, too.
 
@

Latest Lexicon drivers here: http://www.lexiconpro.com/en-US/software

+1 to all of these guys.
 
Another tip for you to relieve frustrations with Win7 (to make sure that Win7 leaves your Lexicon alone): 

1. Check for the newest drivers on your Lexicon.
2. Connect it and turn it on, but do not launch any programs.
3. Hit the Windows "Start" button and type in "Sound" and select "Change sound card settings" from that list.
4. Both the Lexicon and Realtek will appear in that pop-up box.
5. Be sure that Realtek is "Set as Default" on both the "Playback" and "Recording" tabs. You are assigning Win7 "what it can use" here, so it will not nab the Lexicon on you.

   Doing this will ensure that when the Lexicon is online, that Win7 will leave it be. Then when you launch X1, be sure the Lexicon is powered (and connects) before opening X1 each time. X1 can then freely use it in ASIO mode. Powering down, save and close X1 prior to powering off the Lexicon.

Thanks.  I can't believe I forgot the Alpha has output.
 
Now, if I could just get it to install...
 
Mark

I'm still working on the install.
 
Does anyone know - Can I take the audio output from the Alpha into a mixer then into the input of the alpha?  Like if I wanted to mix down a couple midi tracks with a virtual synth from Sonar.  Maybe a mike also.

Hmmm... I you "could" but also run the possibility of creating a feedback loop doing such, so I would not recommend this.
 
Have you gotten your inputs/outputs working? If so, the best "next" step if to download the X1 Reference Guide and walk through the tutorials (they start on page 95).
 
Once you get used to using X1, I think you will find that its mixing abilities will be more than adequate... you can modify and mix down tracks as you choose without the need to run an analog loop to do so... an analog loop will insert signal losses (or feedback loops), as well as require you to edit things "real time" each time. The beauty of a Digital Audio Workstation (DAW) is that you can mix/modify as fast as your computer will carry you.

I can't wait to use X1.  I have been tied up for several days trying to got my Lexicon Alpha to install.  I think myproblem was connecting it before the drivers were installed.  Now the drivers install, but Windows doesn't seem to know to use them when I make the connection.
 

Okay... you installed the latest drivers, have the Lexicon Alpha plugged in to a USB port... If you hit the Windows "Start" button and type in "Sound" and select "Change sound card settings" from that list, you are saying the Lexicon Alpha is not listed when it has power?

Correct.  when connecting the Alpha windows says it is installing an unknown device.  The blue light on the front of the Alpha never comes on.  I took it over to an old XP system and it installed, no problem.