Answer by IamTechCrazy · May 16, 2012 at 01:06 PM
Right click on My Computer and then click Properties.
In the System Properties dialog, click the advanced tab.
Under Performance, click Settings.
On the Visual Effects tab, make sure Use drop shadows for icon labels on the desktop is selected.
Click Ok, and then click Ok again.
Answer by SkinnyBill · May 17, 2012 at 02:06 PM
I think it's to do with the way Windows XP handles certain wallpapers. It doesn't show PNGs like it shows other image types - it renders them with Internet Explorer, and that puts these blue boxes there.
Try to choose a different wallpaper (JPG) and see if that makes a difference. If it does, save this wallpaper as a different type such as JPG
How to remove stuck pixels 5 Answers