I use one of XP Password Recovery CD downloadable from the net to hack into forgotten winxp machines!

This F11 Stuff is new !! I should try it out soon!

It also requires that you already haven't set a password for the default admin account. Also, you can get to the admin account by manually typing the name in at the "welcome" screen by doing [ctrl]+[alt]+[del]

The bet is, this person didn't even try it in his/her own computer.

This is not really any kind of hack. If the original user that installed Windows did not set a password for the Administrator account, then it will be left blank. Anyone can gain access as long as they just hit Enter for the login.

The workaround mentioned by JeremyShaw can be done in normal mode. If you get the Welcome Screen with only the icons to choose from, you can actually force the old login dialog box to show up by hitting ctrl+alt+del twice. If you already see the login box, you can just type in Administrator for the username and leave the password blank.

For those that don't have a password for the Administrator, it's recommended that you create one.

Ummmmmm ... how about:
net user Administrator *

See for example:
http://www.youtube.com/watch?v=BkQmpQB19gs

... one of the many videos that come up when you google for:
site:youtube.com hack xp

when I type this, it asks me the Administrator password. So, if I don't know this password, it's useless. And, if I know administrator's password, I don't need to hack the system...

That only works if the person doesn't have an Admin password. If they are smart they will set a real easy to remember password (for them at least) so incase they even need it they can log in but if you try to you can't (unless you spend all day guessing passwords). Some editions of windows XP howevery you need to type in the username and password (it is not a list). I think this is safer but takes more time. I dont like the whole idea of hacking an Admin account. The owner of the computer could tell exactly who did it once they login and check the control pannel (then they probably wont let you use thier computer anymore).
So I dont see a real use for this unless you get locked out of your own computer somehow, in which case how would you be viewing this site?
Sparkx

And they may simply put a simple Greek or Aegyptian or German sentence, and you will merely not able to pronouce it (simply try to write down "OberSturmführer" without mistyiping !)

Will the wireless internet on laptops get erased if I reboot the computer?

-Micah Anoa'I

Try Ophcrack at http://ophcrack.sourceforge.net

It is a linux distro live cd that find automatically the password of all the computer user's accounts.

Two things, rraallvv :
First of all, this topic is supposed to be a tutorial explaining us the F11 trick. Now we know that this trick does not work. However, the goal of all replies to the present topic should be comments saying "it does not work" or giving complementary information on how to make it work. Other solutions should be made by means of opening a separate topic.
Secondly, pressing the "F11" key is a fully legit operation, it's quite legal to accidentally press the F11 key during the boot.
However, downloading and using things like the ophcrack are completely illegal and are stringly forbidden in most of countries. Take care, I'm pretty sure it's also not accepted by Astahost's forum rules.