Maybe you use your administrator-level Windows user account so rarely that you forgot the password. Or perhaps you've acquired a used PC, don't know the logon password, and have a good reason not to reformat the drive. Either way, if you want to keep using that computer, you have to either find out what that password is or remove it from the logon procedure.
I offered a couple of solutions for this in an October, 2010 Answer Line post. When the piece was published in the February print issue of PC World, it garnered a lot of criticism from readers with easier ways to crack a Windows password.
I've tried some of those suggestions, and there's one I can recommend.
But before I do, here's one I don't recommend: A lot of people praised a free program named Ophcrack, which is apparently extremely simple and very easy to use. Except that in my tests, it didn't work. So please don't write me telling me that I should have tried Ophcrack.
But I have to thank Nicholas Coleman for turning me on to the Offline NT Password & Registry Editor. This one worked quickly and simply, even if the user interface is text- and prompt-based, old-fashioned, and hardly friendly.
You have to boot into this free program off a CD, so it downloads as an .iso file. Double-click that file and Windows just might start a program that burns the disc. If it doesn't, download and install ISO Recorder, then try again. Simply copying the .iso file to a CD won't work.
When you boot the Offline NT Password & Registry Editor, you get a series of prompts. Since it can be confusing, I'll tell you what to type at each of them. I've put the onscreen prompts in italics. After you type your answer, press ENTER.
boot: Just press ENTER.
Select: : Above the prompt you'll see a list of hard drive partitions. Select the right one by typing that number.
What is the path to the registry directory?...: The default is probably correct. Just press ENTER.
What to do?  ->: 1
or simply enter the username...: Type the name of the administrator account. If you're not sure what it is, all of the account names are listed above the prompt.
Select: [q] >: 1
Select: ! - quit...: !
What to do : q
About to write file(s) back...: y
New run? [n]: n
# Remove the CD and reboot.
Contributing Editor Lincoln Spector writes about technology and cinema. Email your tech questions to him at email@example.com, or post them to a community of helpful folks on the PCW Answer Line forum.