There is a menu called "Advanced Options menu" when u boot your computer try pressing F8 and a menu with various options will be displayed...
SAFE MODE is a tool for troubleshooting among other things, driver and network problems.
You will see safe mode, safe mode with networking, safe mode with command prompt, etc..
you will also see "Last Known Good Configuration"
or start windows Normally...
If you for some reason boot up and you are in SAFEMODE .. your computer booted up incorrectly. restart the computer and go to that advanced options menu and try the "Last Known Good Configuration".