Bascud,
We need more info before we can help, this includes are you ok with working inside of a computer and are you aware of the safety steps that you need to take first.
Please provide information about your computer, this includes is it a notebook or desktop, is it a custom build or brand name such as Dell or HP, if a brand name, provide the model name or series number (not serial) if a custom build post the brand and model name or number for the MB, the Ram (including the amount) add on video card if one is used and the PSU (power supply unit) providing these details will enable us to better assist you.