How do I reset Windows Vista password without software?
“I have a PC running on Windows Vista. However, when I left college, I made up a horribly complicated password because I knew my mom would try to break into my computer. I did write it down on a post-it note, but unluckily I lost it. Now I can only log on as a guest and can’t log on the administrator account. I can’t download anything so I can’t download any password recovery software. If you tell me to use some password reset software, maybe I can’t use. So any one know how do I get my account back or any means that can get me into my PC and reset windows vista password without software? Your answer will be very much appreciated.”

Without using any password reset software, without causing any stuff stored on the Vista machine lost, to reset the forgotten Vista password and get access to the administrator account again, system re-installation should not be considered. Well, we can still use a distinctive feature of Windows Vista to reset the forgotten password:

Enable built-in administrator to reset Windows Vista password.

In previous versions of Windows, such as Windows XP, a built-in Administrator account with highest privilege over the whole computer was automatically created and enabled with a blank password, which is a security risk. To better protect the system, the built-in Administrator account with blank password is disabled by default in vista and Windows 7. So, when you forgot your Vista password, you can enable this admin to reset it. Now please follow the below steps to enable Windows Vista built-in administrator account:

1. Log on with the guest account on Vista, then right click computer, and choose Management.
2. Expand Local Users and Groups and Users in the console.
3. Right-click Administrator account and select Properties.
4. On the General tab, clear the Account is Disabled check box.
5. Close the console.
   Now the super administrator account is successfully enabled. Next, you can easily reset the forgotten Vista password from “Start->Control Panel”.

However, if you fail to enable the Vista built-in admin account, then using a third party application such as Password Recovery Bundle will be your best or perhaps the only one choice for you. It won’t cause any data lost and is quite easy to use. Additionally, you don’t have to download this software through your Vista machine, you can borrow a computer to download it and finish the Vista password recovery task on that PC.

Source: http://www.recoverlostpassword.com/article/reset-windows-vista-password-without-software.html