Clean Computer

Hi, i was wondering if you could help me step by step to clean my computer of unwanted processes and potential spyware. My computer has been crashing every so often and when i "report the error" to microsoft it tells me it doesnt know what caused the error. I am not sure if it is some type of error on my computer or if it is hardware related. any help would be great. thanks! -Dan

i am sorry, i think i posted in the wrong place, i will post in the hijackthis group.