This is more a general question than for a specific computer - I frequently need to troubleshoot a wide variety of computers that aren't working properly, and sometimes I run into computers that have experienced a sudden slowdown in performance for no immediately obvious reason (sometimes there'll be a seemingly unrelated cause, like Word spontaneously crashing). I'd like the opinion of some of y'all on what steps you'd take to try to troubleshoot these problems (beyond the obvious i.e. no "check free hard drive space" or "defrag the system drive").