there are other issues affecting it. I would do a clean install
do as per these instructions:
http://forum.notebookreview.com/wind...ta-before.html
install the drivers from the acer page. if that doesnt work, you should make a call to acer and ask for the proper measures for replacement/repair
btw be warned that there are some acers specially the new timelineX series arent holding the charge due to the battery being faulty. However there are people that go overboard on battery, they expect that it would hold the same amount of hours as per the panflets, they wont. Apple currently is the only OEM that actually advertises the right amount of battery, and I can get more of it, due to some measures taken.
For example, people want the backlight while on battery, thats going to drastically lwer the battery life, on my mbp I can get 2 hours more because I turn it off.
I dont surf flash heavy sites nor watch too many stream videos, only videos that I hold in the HD
I lower the brightness to half (usually thats pretty standard otherwise the screen is just too bright for me)
Doing this I can get 9-10h out of it, while the ad says 7h
Regarding the sudden shut downs, its either overheating due to something being quite wrong with it
May I ask what model is your laptop?