Question: I'm going to try to explain this the best I possibly can, but what I want seems feasible. 

I have a studio condensor mic that I use as my microphone input to my computer. When recording I know it is possible to take noise out of the recording by subtracting it from the wavelength. This is often called noise suppression, reduction, or removal. I have speakers on my desk, but the microphone sometimes picks the sound up from there. Is there anyway for my computer to take what is currently being output to the speakers, treat it as noise and remove it from the microphone input in realtime?

I also use the microphone to do voice chat. I have a large room and like to walk around when I talk. Is there anyway to apply a compressor effect to the live input, where when the signal falls below a certain threshold it is boosted and when it goes above a threshold it is softened?

I want to see if I can do this with software instead of hardware.

Edit, I already have wireless headphones but I'd rather not use them since they're bulky.

Answer: 
I'm very surprised that the BIOS is giving the error about something on the hard drive *before* attempting to boot from DVD, and even more surprised that dell was able to mess with the bios prevent booting from DVD if recovery partition is missing. 

What is the exact error?

Perhaps try changing the boot priority so that your DVD drive comes before the hard disk?
There is a wealth of information [Here](http://www.goodells.net/dellrestore/index.htm#dsr-dos) Probably more than you want to know, you may be able to make it useful i.e. make it restore your Win7 installation, or at least make it so small on the disk that it's insignificant, makes the bios happy because it's there, but not taking up any real space.