[nfbcs] Physically cleaning a PC

[Tracy Carcione]

I think it might be a good idea to get the dust out of the inside of my PC, 
but I'm not sure how best to do it.
The instructions I found online say not to touch anything, and to use 
compressed air to blow things clean.  How can I tell if I'm hitting 
everything and getting it clean, if I can't touch things?
I'm sure someone on this list has done it though, so please advise.
Tracy