Is is possible to change the icon of a particular folder (like in MS windows XP, etc), so that it is easily identifiable and strikingly visible.
please advise me.
Yes, this is easy to do. Right click the folder you wish (or select it and use the File menu) and choose Properties.
From there, click the icon button near the top left and you can browse to an image of your choice.
If it's handy, you can also drag and drop an image to that button.
This selection is tied to your user account, so if you ever move the image you have chosen or access the folder from another computer, your custom icon will not be visible.