Sanderxpander
Also, have you checked what's under the "settings" button in that Creative control panel?

Nothing fun in there:
Master sampling rate: 44.1 kHz...
When headphones jack is connected: Two settings...
Enable Bit-Mached Playback...
 
Nothing more..

This may have been mentioned already but on the topic of cables... do you have any cables touching each other or touching any other gear, adapters, computer case, etc?
 
I'm sure this is not the problem BUT it is a good thing to check out when troubleshooting weird noises and ghost signals. I've had all sorts of phantom noises go away after ensuring cables weren't touching each other or anything else. This usually only happens when using cheap cables and gear and/or if something isn't grounded properly.
 
So just for the sake of curiosity take a look around and make sure you don't have any wires crossing each other or touching any gear.
 
 

Just on a hunch, go to Windows sound properties again and check the communication devices. If "what you hear" or "stereo mix" is in there, disable it.
Also, in the Soundblaster mixer app, there is an ASIO tab and an input tab. Have you tried soloing the mic in there?

A few things for you quick:
 
1) If you are seeing this also in Audition, it is definitely in the Creative software, or even Win7. Do you have any of "Enhancements" enabled in the "Playback" section of your card? (Highlight it on the playback tab, hit "properties" and check the "enhancements" tab). Win7 may also be a contributor to what you are seeing (can try disabling enhancements if any are enabled).
 
2) Are you referring to an "impedence matcher" in the comment below? If so, they are a quick way to nerf a microphone (when I first started out years ago I tried this "option" and it is not until you hear the difference between one and plugging into a pre-amp that it becomes obvious).
 

Backstrom No, I don´t have a USB mic. It´s a real one with a XLR to 6,3 millimeter plug and then an 3,5 millimeter adapter so it fits in the soundcard. :)

 
3) I do realize that people start off trying to "make do" with what they already have, and splice everything together to "work." At least you are in the forums so can hear from folks who have "been there, done that." Most music shops have a 30-day return policy, so trying a Scarlett out for yourself may be an option.
 
[The rest below may be superfluous, but is FYI, just in case you go this route]
"IF" you decide to try a Scarlett, and "IF" you want to operate both cards like I do... both devices need to be viewable in Win7, and you must explicitly assign the Creative as "default" (if it already is, assign the Scarlett, then assign back to the Creative). What this does it make Win7 leave the Scarlett alone (even if it sees the Scarlett come on/off-line). Then in X3 you can run ASIO with the Scarlett without Win7 interfering. FWIW, Focusrite has true ASIO aggregation, meaning multiple programs can use it at the same time - I often record in X3 and do noise reduction in Audition without closing either program (I know this works for playback like a charm, but never tested recording).

I fought a loosing battle with a sound blaster PCI sound card for longer than I care to talk about. Not only do they have issues exactly like you are describing, but pour performance, crosstalk, jitters, out of sync tracks and a long list of problems with audio, The drivers even though the say are ASIO turned out to be exactly like asio4all which are not true blue ASIO.  
 
 Defiantly purchase an audio interface. It is the most important purchase for recording with a computer. I wouldn't waste 2 minutes trying to make a Sound Blaster work. 
     If your supper short on banana's then the Scarlett 2i2 will get you going. But look at the Scarlett 6i6 and up as for a few extra bucks you get a lot more features, most important  is the mix control software which the 2i2 and 2i4 don't come with.  There are a few other brands in that price range but Focusrite seems like one of the better companies for support and the drivers are a bit better than most in the lower priced USB interfaces.  
 
When you get the interface you should remove all traces of both asio4all and creative drivers from your system. Even after I removed my Creative card and software and installed the proper ASIO drivers, I continued to get a Creative splash screen warning. I ended up re doing the computer to get rid of it. This Monkey learned to hate the word "creative sound blaster" and so I will continue to throw pooh at it when the word is mentioned n forums...Ook. 

Ok, maybe it´s time for me to say good bye to Sound blaster for ever.
 
I think I´m going to order Scarlett 2i2 and use the motherboards soundcard for everyday music.
And throw away the sound blaster card!!
 
But I dont like that there is no RCA outputs in the rear because I got RCA on my speakers.
Guess I can use two ¼” TRS Jack to RCA adapters?
 
The iTrack Solo got RCA outputs.
Any thoughts about iTrack Solo instead of 2i2?

The speakers only have RCA? Well we may need to talk about monitors next... lol.
 
But the 2i2 will work well. Using some adapters to make the connection would be worth it just to know you have a good, solid interface with proper drivers that will be supported for a long time.
 
Then again I don't really trust anything iThing when it comes to making music so I (or should I say "i") may be biased.

I am biased to Focusrite simply because they have exceeded my expectations.
 
Another "tip" is the software interface (MixControl) can look daunting at first, but there is a really nicely done tutorial posted here (he is using a Saffire 56, so has a lot more inputs). But he talks very nicely to the "logic" and how to use it effectively (and more quickly than just reading the manual). I "believe" the Scarlett uses the same software, but not sure, so wanted to at least let you know this video exists.

If that's the tut I think it is it is most definitely something to watch if you want to figure out the MixControl.... which I probably should even if just for academic purposes. Maybe tomorrow afternoon now that it has been helpfully posted here.
 
Thanks, Mettulus.... and I agree. The Scarlett has definitely far exceeded my expectations by the sheer fact I only had to install it, point Sonar to it (which took like 15 minutes) and never really had to think about it again.
 
It just does what it's supposed to. Awesome.

,, there is no mix control with the 2i2 and 2i4, It starts being included when you get to the 6i6. 
 
Consumer level gear uses RCA. 
 
What sort of monitors are they? 
 
I would purchase a set of RCA to 1/4"  cables as adapters are a source of trouble sometimes.