In safe mode only the necessary application and drivers are enable which allow the user to perform some actions like removing a stubborn application  or a malfunction driver from Microsoft Windows os pc.

<u>Windows 7 procedure :<u>
<ol>
<li> shut down the system completely. </li>
<li>Ensure that the system is completely off (the power indicator is off) </li>
<li> switch it on and start tapping the F8 bottom immediately untill the diagnostic windows show. </li>
<li>select the <i>safe mode with networking </i></li>
</ol>
But for Windows 8: