It doesn't say on Toshiba's site what the memory config is, whether its 1 x 2GB or 2 x 1GB.
The easiest way to find this out without opening the thing up is using a little thing called WMI, now this sounds harder than it is, but I use this all the time to find out memory configs without having to open laptops up.
Open a command prompt as administrator and type 'wmic' the prompt should change to something lie 'wmic:root\cli>' then type 'memorychip' and hit enter, it should tell you what chips you have in what slots and how many slots you have
Once you know what you have onboard you can buy accordingly, make sure you get 1066Mhz speed DDR3 ram and you should be good to go. From what I can see 4GB is the max your machine will take, which is limited by the motherboard. So you'll want to get 2 x 2GB sticks to put in there.
I usually buy my memory from Crucial, it's cheap and reliable.
Here's an useful page for your laptop http://www.crucial.com/uk/upgrade/Toshiba-memory/Satellite+L500+Series/Satellite+L500-1XL-upgrades.html
It doesn't say on Toshiba's site what the memory config is, whether its 1 x 2GB or 2 x 1GB.
The easiest way to find this out without opening the thing up is using a little thing called WMI, now this sounds harder than it is, but I use this all the time to find out memory configs without having to open laptops up.
Open a command prompt as administrator and type 'wmic' the prompt should change to something lie 'wmic:root\cli>' then type 'memorychip' and hit enter, it should tell you what chips you have in what slots and how many slots you have
you can have a look at this link for more details http://www.walkernews.net/2009/11/21/use-wmi-to-find-out-ram-slot-in-used-and-memory-size-of-each-slot/
Once you know what you have onboard you can buy accordingly, make sure you get 1066Mhz speed DDR3 ram and you should be good to go. From what I can see 4GB is the max your machine will take, which is limited by the motherboard. So you'll want to get 2 x 2GB sticks to put in there.
I usually buy my memory from Crucial, it's cheap and reliable.
Here's an useful page for your laptop
http://www.crucial.com/uk/upgrade/Toshiba-memory/Satellite+L500+Series/Satellite+L500-1XL-upgrades.html
Hope that helps.