How to Remove Hiss SOund???

I have recorded a Solo Guitar track. I use a mic (Ordinary mic for Vocals) to put it's signal unto my recording software. When I looked into my Guitar track the signal (waveform) is not visible so I have to boost it up to +18db before I get the Guitar's sound to be audible.

My problem is when I render it as an audio file it has hiss sound. It's fine when I'm listening to it when there is noise in my surrounding but when there is no noise I can here the HISS and its bothering me. Is there any plug-ins that can remove that ambient noise? or the HISS sound that I hear.

Any suggestions will be a great help and appreciated. Thanks!!

You are using Audition, right?  You've come to the right place and can work wonders with a little trial and error.  Go to Edit View > Effects > Restoration > Noise Reduction if you have a few seconds of "open air" to use as a profile.  Be warned... your results can vary from spectacular to awful depending on the settings you use, so read the help file in detail, or the manual, and stop back in here if you don't get the results you're looking for.  Also, if you do a forum search for "Noise Reduction," you'll probably turn up some good gems.

Although you might achieve some success with NR techniques, it seems to me the basic problem is the lack of level in the original recording.  Much better to sort that out than resort to band aid remedies after the event.

Why is it so low?

Although you might achieve some success with NR techniques, it seems to me the basic problem is the lack of level in the original recording.  Much better to sort that out than resort to band aid remedies after the event.

Why is it so low?

Hi! Graeme,
 
I just realized that I didn't state how I connected the Mic into my Computer. 
I am using a Guitar/USB Interface (Behringer UCG102). I plugged a Microphone instead of a Guitar cable into the USB Interface. I used a Philips Mic, It says that it is uni directional design and sensitive 27 mm diaphragm.

Usually I just plugged in my Classical Guitar into the Interface however, I can't achieve what I want the Classical Guitar to sound when it is plugged in and I'm using its built in mics. So I decided to record it using mic. I manage to achieve the sound that I like somehow but the problem is the Hiss. Is there anyway that I can share my recorded track here so you can have an Idea on what its sounds like?

It's an electronic mismatch and Graeme is right -- the level, consequently, is far too low.  You need a proper mic preamp to do this right, not a guitar interface.

Is there anyway that I can share my recorded track here so you can have an Idea on what its sounds like?

No need * - now we know how you are using your equipment, I think we all know exactly what it sounds like and it won't be pretty.

As MusicConductor has already said, you need a proper mic pre-amp.  This will both match the mic impedance properly and provide considerably more gain.  A guitar pickup will output signals in the order of 100's of mVollts, whereas a microphone will rarely develop more than a few 10's of mV and your purpose designed guitar interface will not amplify the signal enough.  This is your fundamental problem, not enough level into the recorder, resulting in a hissy recording.  Sort this out and all will be well.

* You can attach a file quite simply.  When writing your message, click on "additional Options" and follow the instructions there.