encoding

i helped a friend's laptop, xphome, recover from a virus and his comp was fine except encoding default was unicode instead of western eurpean. changing it or selecting autoselect won't permanently keep a setting . it always reverts to unicode. i think that is why some web images do not appear. i updated his comp to xps2 w/ all critical updates (that went fine) but problem still persists. the only fix i found is perhaps uninstalling and reinstalling ie6, but the problem also exists when he uses aol as browser. the comp runs fine in all other respects. Any thoughts? thank you in advance