My computer is borked

My name is Savannah and I am an artist.
I have been on the freelance scene for two years now, work is slow but I mange. About half way through my second year I put money in to a desktop computer to transfer from using my laptop. It was great! I invested in to having two screens and it has been a lot more comofrtable than staring a small screen for a few hours a day. 

The computer has been running smooth and perfectly...until recently...







(Check out my fantastic setup, aw yeah)

There is something missing from these three photos can you tell what it is? Yup, that fantastic computer. The processor has decided it would up and die on me, so back to using the laptop. I had given the whole unit to a friend to look over and told me the cost of a new processor, installing and putting it all back in to the unit. 

Help from other people!
I do not have the spare funds to get a new processor and get it installed correctly

I am looking for at least 100 dollars, that amount will keep me from falling in to a hole once everyhting is said and done. 

Getting this computer back up and running will allow me to contiune my treck of artistry and all help given will be appreciated.