If coloured boxes have appeared behind the icon labels. Try this:-
Start-->Control Panel. Double click the System icon. Click the System properties tab. Click the Advanced tab. Under the heading Performance, click the Settings button. In the Performance options window click the Visual effects tab. Ensure that the chosen scheme is Let Windows choose what's best for my computer. In the lower pane make sure all the boxes are ticked, especially the item labelled Use drop shadows for icon labels. Click Apply (unless the apply button is greyed out). OK your way out to return to the Desktop.

Icons have vanished from the Desktop, also the Notification area hides icons. To stop this silly behaviour, right click the Taskbar.
In the Properties window, all the items should have their boxes ticked. The following two should not have their boxes ticked.
         Auto hide the Taskbar
         Hide inactive icons
To tick or un-tick a box just click it.
To finish, click Apply and then click OK

Now right click an empty area on the Desktop. Click Properties. Click the Desktop tab. Click the button labelled Customize Desktop. Un-tick the box labelled Run Desktop Cleanup Wizard every 60 days. Click OK. On the next window click Apply then OK.

If your TFT (thin flat) monitor suddenly displays snow instead of your desktop picture with icons, it is looking for a TV channel and it can't tune in. Don't panic nothing has broken either in your computer or in the monitor. You have dual purpose monitor (TV and PC) and you accidentally pressed the TV button on the front of the screen. To change back, most dual purpose TFT monitors have a button labelled Source. Press that and use the buttons marked with little up and down signs to put it back to the PC setting.