I am sorry, but you need to click on the "Display" tab up top and screenshot that.
If I am not mistaken though, it has integrated graphics, and this type is very, very weak. You need to get a standard graphics card for CS:S to run smoothly.
You also have to look at what kind of bus type you have. I have done some research and found that it only has PCI slots. PCI slots are the oldest and most outdated of the 3 types of cards made. You need to know that even if you do upgrade you are not going to be able to play most newer games smoothly, but you can run CS:S Smooth with the right card.
Here is a good thread that is based around PCI GFX cards.
Where do you live? If you live in the US, you could go on ebay and get the 8500GT PCI card, it was only released in the UK if I am not mistaken.
Other than that the X1500 is your best bet.
Newegg.com and tigerdirect.com is two good websites to buy from.
IF you are looking to not buy anything, then you could try this:
Open up steam, right click on Counter strike source>Properties>launch options.
Put this here, without quotes: "-dxlevel 60" or "-dxlevel 70".
Note that this will greatly reduce the quality of the graphics, but makes it playable, I hope. Also this can cause some servers to kick you, because it is supposed to give you an "advantage" that I have yet to find.
Also, if you haven't already, try turning the graphics down. Go to options, video, and turn the resolution down to 800X600 or 640X480. Go to "advanced" and turn everything to the lowest it will go.
Good Luck!