This can happen if you have a mismatched copy of shdocvw.dll in your Windows
directory.
Explorer relies on the correct copy being in the windows\system32
subdirectory.
From the blank screen state....
1) Press CTRL+ALT+DELETE, and then click Task Manager.
2) On the File menu, click New Task (Run).
3) Type: cmd.exe, and then press ENTER.
4) Type: cd\windows, then press ENTER
5) Type: ren shdocvw.dll shdocvw.old, then press ENTER.
6) Restart the computer.