I installed Win 8.1 on a 3-4 year old Acer 5253 for a friend. I upgraded the memory to 4 GB & the laptop seems to be working fine. Occasionally when you plug the charger in the charging light doesn't come on, though usually it does. I've charged the battery several times to 100% but today it reached 96% and stopped. Now when I plug the charger in the charging light starts blinking, which it never did before. Most of the posts in this forum re: charging problems discuss changing the charger or battery. The owner bought a new battery a few months ago. Do you suggest buying a new charger, or could something else be causing the problem? I've taken the battery out & reinstalled it a couple of times but it still does the same thing.