Blank desktop on Logon

Some times when something is installed or un-installed, default shell value is supposed to be configured to new one and it actually neither changes to the new one and instead removes default that is Explorer. It can also happen as a result of a virus attack especially something like W32.Blaster.Worm.
It results in such an awkward situation that you don't get anything on desktop, except for the wallpapers, and you're shocked to see that all your icons are gone (at least not visible) and your starting point, the start taskbar at the bottom is also gone and you don't know what to do.
The solution is quite simple if you can toy around with the registry a lil' bit. Follow these steps in order to get back your icons and taskbar.
i.) Press 'CTRL+ALT+DEL'
ii.) Go to the first tab - 'Applications'
iii.) In the bottom you'll see 'New Task' button, Press it.
iv.) In the window that pops up write 'regedit' (without quotes), and press 'OK'.
v.) In the left hand pane go to HKEY_LOCAL_MACHINE and expand it to go to Software then move to Microsoft to Windows NT to CurrentVersion and finallly to WinLogon, here in the left hand pane youll see Shell, double click on it and enter 'Explorer.exe' (without quotes)as value data in the window that pops up and press 'OK'. (and if you have experience with regedit then simply it is that browse to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\WinLogon\Shell and changet the value to 'Explorer.exe (without quotes)')
vi.) That's it, you're done. Just logoff and login, and you'll get all your icons and taskbar back.