Find mic installed in laptop

simply visit Acer Service Support then click on "Drivers and Manuals". Then in model search type 7741z. It'll then show list of drivers and manuals under documents for your laptop.

Do you need webcam drivers?
Drivers and Manuals
type in your laptop model here and choose webcam driver, follow the steps to install it

goto your start menu and typ in restore it should give you all you need to know

Sounds like you need new batteries. If the charging light comes on then the battery has reached the end of it's life.

If you have a multimeter, it'll be easy.
Plug the Acer Aspire 7741z charger in, test the connector of the adapter with a multimeter, remember, you only need to measure the DC voltage of the adapter.
If the readings are close to the specification on it's label, then the charger is OK.
If you do not have a multimeter,
Turn the computer completely off and remove the battery,
then check out whether you can
power up the Notebook with AC power only (no battery installed).
If you can power up your laptop, then the battery is dead.
If you still cannot power up your laptop,the adapter defective and you need replace it.

Have you tried a cold start, unplug, remove battery, hold down on/off button for 10 seconds, replace battery, plug in start normally. If that fails re start while tapping F-8 repeatedly until it boots into Boot options. Repeat if necessary. that's a good place to start

its b'cu'z of memmory failure
replace your memmory.
then let me know how it works

Here is the Guide for your Acer..

http://www.laptop-software.com/acer-software/acer-aspire-7741-7741g-7741z-7741zg-notebooks-guide/

Thanks for using FixYa - a 4 THUMBS rating and POSITIVE TESTIMONIAL is appreciated for answering your FREE question.