Unaffected vs Uneffected

'Unaffected' means 'unchanged, uninfluenced, untouched'.

Examples of 'affected'and 'unaffected': 1. Apply the antiseptic cream to the affected area of your skin. 2. She remained unaffected by her husband's death, and carried on as normal. 3. There were floods all around us, but we weren't affected, because we are on higher ground.

http://grammar.yourdictionary.com/style-and-usage/affect-effect-grammar.html

"Unaffected" has the same etymological root than the french word affectation which is used in computer science when assigning a value to a variable. The word "affectation" has also another sense related to a pretentious, unnatural or not sincere behavior.

Then "unaffected" is synonym of "unassigned".