hi hrairoorah
Ya sure u can change my computer icon easily without changing as a whole icon set.... in easy steps
Step 1: Go to 'Desktop' (Ctrl + D) -> Right click -> Properties
Step 2: Move to 'Desktop' tab -> Customize desktop -> 'General' tab -> select the item which you want to change and click change icon
Step 3: Select ur favourite icon (either from system icons or from ur downloaded set).
Step 4 :Click 'Ok '.
to see the picturized tutorial visit our blog
http://www.techtutr.blogspot.com/
regards
Tech tutr