If you want to change the password of any user account you can do it by following this steps:
At First boot you system into Safe Mode. To go to xp safe mode Restart your system
and press the  F8 key. (when your pc being restarted) Now you will see a  menu. Use the keyboard arrow keys to highlight SafeMode then press Enter & press Enter again on Windows XP now your pc will start in Safe Mode.

You will get Account Log on Screen. click and logon the administrators account. Now have fun with hidden Admin Account.

Here is a trick to Hack System privileges

Open a command prompt (Start -> Run -> Cmd -> Ok),

-Then type: at ##:## /interactive “cmd.exe” (##:## is time one minute from now in 24hrs. eg 5:30pm=17:30)

-When it gets to the time you specified, a new command prompt should open,

-So open the task manager (press CTRL+ALT+DEL or type taskmgr in command prompt) and end the “explorer.exe” process (Everything on the desktop will disappear, but the command prompt will stay),

-Then type explorer.exe (A new desktop should appear).
-And you now have System privileges.

With this you can open executable file extension, play games, surf the web easier, change administrative passwords, whatever. Good for getting around things at work or school…. = FULL CONTROL

I collected some User name and pass for Routers. Sometimes it comes handy while creating a wireless network.

Brand > Default Address > Default Username > Default Password
Belkin > 192.168.2.1 >
D-Link > 192.168.0.1 > admin >
Linksys > 192.168.1.1 > admin > admin
Netgear > 192.168.0.1 > admin > password
SMC > 192.168.2.1 > smcadmin
Zyxel > 192.168.1.1 > admin > 1234