Desktop

Please make sure that you are not using an inexpensive power supply and that you have enough watts.
Also, always make sure that for every software installed that you can start only when you need it, is not running in your system tray and using up CPU.
Make sure you are conserving power by allowing your pc to rest when you do not need it.
Also ensure that as you add new peripherals and hardware to a pc that the CPU can handle it, and that you have enough memory to go around.
Lastly, clean that PC inside every five or six months.
Last year I serviced so many pcs that were dying because they were dirty.
Stay away from toolbars and remember that AOL and other system intensive programs often packaged with DSL or mass produced machines like HP system care stuff and the like, these are all system hogs and I have found most of them to be unnecessary.
As for cleaning pcs, I do not use compressed air anymore. I have switched to a very small vaccuum attachment and a static free artists brush and I have had great success.
I also am starting to replace my thermal paste on my cpu every year, since the last time I cleaned my cpu fan, the fan unit was stuck to the thermal paste and the thermal past was hard, so I replaced it.
I do not know everything, but I am learning as I go and hoping my spelling is not too bad as well.
I hope some of these tips help and have a blessed Holiday.
Doodad