I was forced to change my Windows password frequently at my old job which sometimes led to the situation that I could not remember the new password on the next login. This happened for instance when I changed the password on the last day just before going on vacation. I had to contact the IT department to reset my password. There is an easier solution for computers with direct access.
I know that many users reinstall Windows if they have forgotten their password because they cannot figure out how to get into the system again. I’m using the Trinity Rescue Kit to reset the Windows password so that this is not necessary. You actually have the choice between setting it to a blank password or changing it to a new one.
It can be run from a bootable CD, USB device or network over PXE. The bootable CD is my choice and I always keep one around in case of emergency. Just boot from the CD if you cannot login into Windows anymore because it prompts you for a password that you cannot remember.
You can start once the message “Welcome to Trinity..” appears on the screen. Use the command winpass -l to list all usernames of the system. Now enter winpass -u (for instance winpass -u Martin). This will lead to a series of dialogs, make sure to press n when asked if you want to deactivate Syskey.
You are given a choice to (1) remove the password, (2) set a new password or (3) make the selected user an administrator of the system.
That’s actually just one tool that the Trinity Rescue Disk offers. I could write about other useful ones if you like. Oh, one last remark. The file system is based on Linux which means that you will not see the usual c,d,e drives like you do in Windows. Hda, hdb, hdc are the hard drives connected to your computer and the numbers behind are the partitions of those hard drives. Hda1 for instance means the first partition of the first hard drive which is usually the location of the Windows installation while hdc2 would refer to the second partition of the third hard drive.
Note: If you are using Bitlocker Encryption then you won’t be able to access the encrypted data after resetting the password. To be on the safe side, create a backup of the system partition first before you are running any operation using Trinity or another option.