On my computer, this is how I take a screen shot...
Get whatever you want to take a shot of on your monitor (in this case, I'm guessing your browser). Click on the Windows Start button at the bottom left of the screen. Hover over "All Programs," then scroll to "Accessories." Click "Snipping Tool." Your screen will gray over, the cursor will turn into a "+," and a dialog box will pop up and float on top. Position your cursor to one corner of the area you would like to include. Click and hold the left button while you drag the cursor to the opposite corner, then release the left button when you have included everything in the image. A new dialog box opens containing your screen shot, with a menu at the top. I click on "File," then select "Save As" from the drop down menu. Navigate to the intended folder and then name it and click "Save."
There might be an easier way, but this is the method I know. HTH