Is it safe to clean the outside of my pc with a vacuum cleaner?

[The Conjurer]

So, a day ago I cleaned the outside of my pc with a vacuum. I thought it was safe since i wasnt doing it around the actual components(this i usually do with compressed air). I cleaned out the places where my fans are - front and top of the case. But my friend tells me i should have at least plugged in the psu so the pc would be grounded (i dont know why i didnt think of this myself), and that even though my pc is fine now the static could have caused damage which could show itself later on. So , what are the chances of this happening? I may be paranoid about this but everything i do is on my pc-my work, stuff for university, and all of my hobbies involve my pc.

 

[RCFProd]

Really I wouldn't worry, but I prefer to use clothing and a dust cleaner instead.

 

[Kryptkeeper]

keep it grounded just to be safe, its unlikely to cause any actual damage. and if it has done any damage already then there's not alot you can do about it, but if it works it works.