Do you have a mac or just your XP PC?
On your mac can you open the HDD then open applications then utilities andopen the Airport utility,
When it opens can you select your airport on the left hand side then choose configure and then click the Password XXXXX at the top of the window.
Once you are there your password XXXXX be listed so you can then write it down.
Let me know if you have any issues
Did it say wireless password XXXXX wireless equivalent password?
Can you try this for me,
Highlight your AirPort wireless router from the list of available devices on the left side of the airport utility window. Then click on the Manual Setup button at the bottom of the window and go to the Wireless tab at the top of the window, Then can you enter a new password XXXXX your AirPort wireless network in the Wireless password XXXXX and Verify Password XXXXX then can you click on the Update button at the bottom of the window to save the settings and change your AirPort password.
After you have done that can you then try connecting with the new password XXXXX just set
The wireless password XXXXX XXXXX security key you need to connect wirelessly.
If you go back to the wireless setup in the airport can you tell me what your wireless security is set to, Such as WEP, WAP, WPA-PSK
And can you tell me ifi t then says TKIP or AES?
Then can you click start then run and type winver and hit enter and let me know if your XP version is SP3 or Service Pack 3?
Can you change the security type to WEP then enter a 10 digit passphrase into the airport and save your changes then let me know if you can connec the samsung
Glad you got it sorted out.