System password does not work cannot start up.

You cant log in ?
Restart your computer repeatedly tapping the f8 key to enter safe mode while the screen is black once in safe mode where the only things working will be your keyboard and mouse allowing you to attempt to repair your computer Windows Advanced Options Menu Please select an option: Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt Enable Boot Logging
Enable VGA mode
Last Known Good Configuration (your most recent settings that worked)
Directory Services Restore Mode (Windows domain controllers only)
Debugging Mode Start Windows Normally
Reboot
Return to OS Choices Menu Use the up and down arrow keys to move the highlight to your choice select safe mode with command prompt Click start run type cmd press Enter black screen should open DOS mode this will vary depending on your operating system type in net user username For eg. If you want to change administrator password , type net user Administrator It will prompt you to enter the new password. Enter the new password and the password is changed if this fails you will need to Select safe mode with networking to download you could download all of these or just one save them to a usb drive for later use if one fails to remove the password Windows Password Recovery Basic http://majorgeeks.com/CmosPwd_d239.html A CMOS BIOS password recovery tool Editors note: This tool should only be used by experienced computer users. Please see the enclosed read me if you would like to run it from Windows. Failure to follow instructions (from Windows) will cause your anti-virus to flag this as a virus. http://majorgeeks.com/Dr._Freeware_System_Utilities_d6416.html Dr.Freeware System Utilities which includes data recovery software, data backup, password reset tools for Windows helps you to maintain your system. Dr.Freeware is freeware, you can download and use it for free. Hope this helps.