Comp Crashes/COM+ Error

My comp randomly turns off. I cleared all I could out of my start up. On Event Viewer it says that COM+ keeps having errors I dont know if that has anything to do with it. I cant even run a virus scan because if I do the comp uses all of its resources and turns off. This comp used to be fast I dont know if its because of viruses or what but I cant even scan for any because if I try the comp crashes. Can anyone help me fix this problem? :cry