I already have the sample rate set for 44.1, ski sorry about the term sound card, I was referring to the fast track pro, my studio interface. I also tried to change the Mic

No need to apologize. I'd call it a sound card too.
 
I was grasping for possible reasons. :-)
 
The Fast Track should do 24 bit no problem. If you are setting it to 24bit and finding it defaults back to 16 check SONARs options for Record Bit Depth and Default project Bit Depth.
 
Which driver are you using? Is it possible you are using MME when you have other choices? What does it say in SONAR's Audio Options?
 
best regards,
mike

According to the manual for the M Audio Fastrack Pro it supports 24 bits.
 
 
"Supports sample rates up to 96kHz with full 24-bit resolution
Functions as a stand-alone 24-bit/44.1kHz A/D converter"
 
Copied from the features on the 1st page. 
 
I think you have it set up wrong and you may have not set Sonar's render bit depth to 24 bits. 
 
Your audio card is very capable of 24 bit recording. 

A few things to try:
 
Set up as you usually do with the mic going into the Fast Track's mic pre input. Set the Fast Track input level as usual.
 
Unplug the mic lead from the Fast Track (so there's nothing connected) then record. Do you get silence or hiss? If hiss, how loud is it (what does the track meter in Sonar tell you)?
 
If no hiss, then connect the mic and lead. Make sure the mic is pointing at nothing (especially your PC) and sit it under a cushion. Record. Is there hiss now?
 
Finally, are you sure the hiss isn't the "blow"noise from your amp being picked up by the mc, or the fans in your pc, or air conditioning or anything else external? Our brains filter out background noise, especially low-level noise we're used to hearing all the time. Until we start recording audio, when it becomes painfully obvious :-).