you should have written it down somewhere safe so anytime you need to get on your network you have it handy, did they maybe tape it to the bottom or side of the router?

if not this program will find it for you
WirelessKeyView v1.34 - Recover lost wireless network key

any computer that you will want to allow on to your wireless network will need that passcode so once you have it write it down and tape it to the router somewhere but do not block the vents.

also the wpa password is NOT the same as the router password the router password is what you need to gain access to your actual router settings.

Thanks Raven...I was going to use that program but reviews say it has nothing but malware attached to it...no I can't find anything that they gave me that has the password. I usually have no 2nd quess in what you recommend but this program scares the crap out of me.

Just change it to a new one in the router.
Easy if you have one wired computer... but not a big deal(usually) if all are wifi.

May not work with netgear but worth a try. I was asked to find the password on a computer with a linksys router attached. I found a lynksys folder on the c drive and opened it. The first file in the folder was a text file and when I opened it the password was there.

I have never had a problem with any nirsoft products, have recommended this tool here previously and it was used and it got the password for the person. Nirsoft is a well known brand. It is recommended at lifehacker also
Reveal Wi-Fi Network Passwords with WirelessKeyView

this only allows you to use it on your pc and gain access to your password it is not a tool that can be used to gain passwords of others. You have to have access to the pc that you are wanting the password of the network.

You can always use it then just remove it once you have your info.