Ok... try this :
<h3><span style="font-weight: bold;">STEP 1 :</span> Start your computer in <span style="font-weight: bold;">Safe Mode with Command Prompt</span></h3>
<ol type="1">
<li>Remove all floppy disks, CDs, and DVDs from your computer, and then restart your computer.</li>
<li>Do one of the following:
<ul>
<li>If your computer has a single operating system installed, press and hold the F8 key as your computer restarts. You need to press <span style="font-weight: bold;">F8</span> before the Windows logo appears. If the Windows logo appears, you will need to try again by waiting until the Windows logon prompt appears, and then shutting down and restarting your computer.</li>
<li>If your computer has more than one operating system, use the arrow keys to highlight the operating system you want to start in safe mode, and then press <span style="font-weight: bold;">F8</span>.</li>
</ul>
</li>
<li>On the Advanced Boot Options screen, use the arrow keys to highlight <span style="font-weight: bold;">Safe Mode with Command Prompt</span>, and then press <span style="font-weight: bold;">ENTER</span>. For more information about options, see <a href="http://windows.microsoft.com/en-US/windows-vista/Advanced-startup-options-including-safe-mode" rel="nofollow">Advanced startup options (including safe mode)</a>.
<img src="http://i.imgur.com/lGBtd.jpg" alt="[Image: lGBtd.jpg]" border="0" /></li>
</ol>
<hr />
<h3>STEP 2: Remove the malicious registry key and file</h3>
<ol type="1">
<li>When Windows loads in 'Safe Mode with Command Prompt', the Windows command prompt will show up as show in the image below. At the command prompt, type <span style="font-weight: bold;">explorer.exe</span>, and press <span style="font-weight: bold;">Enter</span>.
<img src="http://i.imgur.com/cPSFH.png" alt="[Image: cPSFH.png]" border="0" />
<span style="font-weight: bold;">The Windows Explorer will open, do not close this window. </span></li>
<li>Using the same Windows command prompt,type <span style="font-weight: bold;">regedit</span> and press <span style="font-weight: bold;">Enter</span>.
<img src="http://i.imgur.com/0Lwph.png" alt="[Image: 0Lwph.png]" border="0" /></li>
<li>The Registry Editor will now open and you'll need to browser to :
<span style="font-weight: bold;">HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\</span> and search on the list to the right for an registry entry named <span style="font-weight: bold;">Shell</span>.
<img src="http://i.imgur.com/trAD8.png" alt="[Image: trAD8.png]" border="0" /></li>
<li>Right click on this registry key and select the “<span style="font-weight: bold;">Modify</span>” option. Its default value should be '<span style="font-style: italic;">explorer.exe</span>' however this infection modified this entry.</li>
<li>Before you rename this registry entry to '<span style="font-style: italic;">explorer.exe</span>' , copy the location of the modified value to a piece of paper or Notepad because this value will point you to the ransomware executable file ,which needs to be removed.
In our case, the malicious file is running from the Desktop and it's called “<span style="font-style: italic;">contacts.exe</span>”, but the cyber crimanls may have changed the file name in your case so it might have a different name.
<img src="http://i.imgur.com/nlgsb.png" alt="[Image: nlgsb.png]" border="0" /></li>
<li>Modify the value of the registry entry back to '<span style="font-style: italic;">explorer.exe</span>'. Click <span style="font-weight: bold;">OK</span>to save your changes and exit the Registry editor.<img src="http://i.imgur.com/vMPAe.png" alt="[Image: vMPAe.png]" border="0" /></li>
<li>Browse to the location indicated in the value of modified registry entry and delete the malicious file. In our case, the malicious file was running from the Desktop and it was called “<span style="font-style: italic;">contacts.exe</span>”.
<img src="http://i.imgur.com/0nKTO.png" alt="[Image: 0nKTO.png]" border="0" /></li>
<li>Go back into "Normal Mode". To restart your computer, at the command prompt, type <span style="font-weight: bold;">shutdown /r /t 0</span> and press <span style="font-weight: bold;">Enter</span>.
<img src="http://i.imgur.com/JQx7q.png" alt="[Image: JQx7q.png]" border="0" /></li>
</ol>