Ok, as an Acer Aspire 4741G User. from what knowledge I have is that this laptop has a max of 2 memory slots on the motherboard. Originally the laptop comes with a 1GB Memory on each slot, so that's how it will show you that you have 2GB as memory capacity.

TAKE NOTE
>> The 4741G Model need to have a [/U]PC3-8500 DDR3 SDRAM SODIMM 204pin memory type.

The slots has a Maximum capacity PLEASE take note of this also !! The maximum amount of RAM you can upgrade for this 4741G model is 8GB Max !

So, this means you can only install 4GB Memory on each slot to get that Maximum 8GB.
And make sure you get the correct Memory type as mentioned above. AND also be very sure that making this memory RAM to work, is a whole complete different thing altogether.

It is NOT as easy as you think. If you are going DIY on this, be ready to have several issues popping up, such as Freezing on windows start / boot screens. Non-compatibility issues. The Boot or BIOS errors that you may face. My expert advice is DO yourself a favour. GET the memory card and upgrade it using some experts on this. Get to a SHOP or a repair/upgrade specialist to do this for you.

Yeah..it may cost just a bit more, BUT its really worth all that Headache and effort TRUST ME !!! Ask the specialist fella upfront if he can help upgrade your mem on your Laptop. If he/she says can, THEN go ahead buy the appropriate card and then give it to that fella to Fix it.

And oh yeah, I will be upgrading my RAM on my 4741G VERY SOON also ! Cross Fingers and PLEASE pray for the success.
If its successful, I will then be replying here on how you can go ahead to do it.

Be a Fix-it-Felix, don't be a Wreck-it-Ralph !!!
LOL !

I have recently upgraded my RAM to 8GB (4GB + 4GB).
Got a computer technician to do it. So far so good.