Edit I notice you posted while I was writing this Yet I'm still gonna leave this as I wrote it …
Well it is apparent that you seem to be getting some pretty decent advice here from the posters that have tried to help you so far …
depending on who you ask , it may go downhill pretty fast from this point on w me trying to help you out
I have the 2i4 myself , at first it was a little problematic for me…( this was about a year and a half ago )
the 2i4 seemed OK in SONAR but in another program I liked to use I was getting major buffer overloads….
to give you an idea of what type of problems I was having on my lap top …( W 8 64 bit ) running ASIO
the "then current driver " did not have a section that came up in the control panel where I could access my sound card and set my buffers and sample rate to taste …
I had to do it inside of SONAR …( I thought that was a little weird )
I got major system buffer overloads regardless of using buffer sizes 4 times my preferred compromise setting
my compromise setting is 512 in ASIO ….
I wound up contacting tech support and did a back and forth correspondence with the tech that was assigned to help me out …
Having had a good experience w the tech may I suggest to you that it may be a good thing for you to consider …open up a support correspondence w Focusrite ….
What eventually happened was the tech sent me a link to a beta driver for W 8 . since then everything has been working fine ever since …my device shows up in the control panel , and it runs very good
another thing to consider , since your other sound card had extra USB ports for all you other peripherals …..
Did you get used to having all of those extra ports and decide to try to run you 2i4 connected to a hub ?
The 2i4 has to have it's own USB hub

I found this one for myself …..
I have a feeling that the 2i4 may draw a lot more USB resources than some other USB sound cards …
Somebody I know want's to give me an XP lap top that is collecting dust ….(once he finds the charger )
I plan on trying out Linux on this lappy…I have no experience w that OS so I feel it may be a good machine and place to start .
I did a little research on compatible sound cards for that OS ….
my other USB sound card was listed as compatible on The Wiki ….when I looked up the 2i4 , it was listed as compatible in that OS , but it stated plainly that in that it had to be powered by and externally powered USB
hub before going into the computer …
that little tidbit / info is where I got the impression that the 2i4 may need to draw a little more than some cards
good luck to you I hope you get it sorted out ,
Kenny