This is quite an attractive feature in Windows as this kind of highlights the icons in the desktop from the back ground. But if you have a white back ground or a back ground similar to that of the icons then this feature may result in difficulty in reading the text under the icons.
Hence if you wanted to disable the shadowy appearance under the text in the desktop icons then you can do it easily by following the steps given below.
Open control panel (start > control panel)
Then open the system properties, by clicking on the system icon.
Open the advanced tab, and under the performance section click on the settings button.
Find the entry “Use drop shadows for icon labels on the desktop” and uncheck it and click Ok.