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Is it possible to set up a USB Drive to automatically log into Windows (xp, Vista or 7) without installing any specialist software on the PC?
I've had a look at:
But this needs a 3rd party application and I was wondering if there's any way to do it natively?

The machines I wish to log on to are in an open access communal area so not having a password is not an option. (I also wish to log in as an Administrator so its even more not an option)

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There's a very similar question to this on the ServerFault sister site – GAThrawn Nov 10 '10 at 16:48
Unfortunately the answer posted is not what I'm looking for. i want one USB stick that I can use to log into multiple machines. Buying Hardware for the machines isn;t cost effective when i only log in rarely. – Joe Taylor Nov 10 '10 at 17:03
up vote 1 down vote accepted

Take a look at YubiKey. Although you mentioned not wanting to add new hardware, this doesn't require any new computer hardware. The YubiKey is a small thumb drive sized device that pretends to be a keyboard. Thus, you can stick it in a computer and have it input a password.

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What you are asking is not possible with out a service installation sadly. I've looked into doing something similar and was not able to find a native way to do this (at least with XP and 7).

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Did you find another way to do it? – Joe Taylor Nov 10 '10 at 16:59
Did you find another way to do it? – Joe Taylor Nov 15 '10 at 13:24

One method for achieving this in Windows itself is a utility called "Syskey" that can be run from a standard 'Run...' or Start Menu Search prompt. I'm not sure how far back the feature goes but I personally use it on Windows 7.

Running syskey allows you to encrypt your accounts database for additional security. By default the encryption key is stored locally on the drive windows is installed upon. However you can set a floppy drive to hold the key as well, which means that to access any account on the PC that floppy needs to be inserted first. The trick though is that by default Windows reserves the A: drive for 3.5-inch floppy use and B: for the older 5-inch floppy. That can be used to make ANY drive, USB or otherwise, recognized by windows as a floppy drive, even at the DOS / shell level.

Set the drive letter of the USB drive to 'A' by going to My Computer and right-clicking on it. Select "Manage" from the rollout list, then select Disk Management from the window that opens up. Right click on the USB key in the right sided pane, then select "Change Drive Letter and paths…" to bring up a dialog. There you can choose a drive letter, and simply choose 'A' from the list. Note that any existing drive set to use A: will need to be similarly assigned a different drive letter before the A: label will appear in the dropdown list.

Upon booting Windows, you should now be asked to enter the key disk before you can log into an account. If you have windows set to log in automatically then just pop in the USB and hit Enter. With log ins required it will instead take you to the account log in screen.

PLEASE NOTE, this process sets your Windows installation to REQUIRE the USB drive be plugged in any time an account action is taken. You will not be able to access or recover your Windows installation without the USB drive.

The key file itself is called "syskey.key" and should never be touched. It is a constantly changing file too, so you can't simply make a copy for backup or multiple users. Reversing the process can be done by running syskey again and telling Windows to store the key file locally.

I know this is an older question but I just spotted this randomly in a Google search and decided to help anyway. I get a lot of indirect help from this site so it's nice to give back. :3

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You're talking about SmartCard support that has been built into Windows for many years. I have not set up such a system but know people who have. The first step is buying a few smartcards for your experimental use and becoming familiar with Windows intrinsic SmartCard features.

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A nice writeup here:, which me wanting to learn how to do this myself. – Robert Kerr Nov 15 '10 at 17:55
See my comment attached to the question. I do not want to purchase any extra hardware – Joe Taylor Nov 16 '10 at 9:02

See this thread : How to Login to Windows XP/7 Using a USB stick for authentication.

One of the answers mentioned KON-BOOT which can let you boot on to a computer (not the domain):

Kon-Boot for Windows enables logging in to any password protected machine profile without any knowledge of the password. This tool changes the contents of Windows kernel while booting, everything is done virtually - without any interferences with physical system changes.

It sounds like a very dangerous hacking tool.

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I've been able to find this, however it's for mini Win98. I suspect it could be leveraged to do XP but it's probably going to take a little more work.

Here's the link:

link text

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That's to create a USB Boot Disk, not to log into Windows. – Joe Taylor Nov 19 '10 at 9:34
Apologies, I misunderstood. – QuiXilver Nov 19 '10 at 11:13

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