How to unlock Windows Administrator Password
1. Boot the Windows installation CD, select Repair your computer. (For Windows 7, select your language before repair your computer)
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2. Select Troubleshoot. (For Windows 7, skip the system recovery and go to command prompt)
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3. Select Command Prompt.
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4. Change directory to d:\windows\system32
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5. Type copy utilman.exe utilman.exe.bak (to Backup utilman.exe)
Type move cmd.exe utilman.exe (to Move cmd.exe to utilman.exe)Type Y to overwrite.
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6. Restart server and boot windows as normal.
Press “Windows Key + U” to open command prompt.
7. Type net user administrator password
Password = new password
8. Close command prompt and log in with new password.
Optional
You can open user account settings with GUI by using netplwiz command.