I have Windows 2000 and my netgear wireless - n - usb adapter wna3100 will not install. I get an error each time.

Your device is not suppoted by Win7.
NETGEAR Support Answer NETGEAR Product compatibility for Microsoft Windows...

It may not be compatible with Windows Vista Home Premium.

It might not need for WIn8 to detect the adapter. when that screen appears cancel/close of otherwise kill the process and see if the adapter is recognized in Device Manager without any error icons.

It looks like your NetGear WNA3100 is dead out of the box.
The software looks like it operating correctly (runs the installed diag, tries to detect, etc.), but
the software isn't having any luck finding the hardware.
The reason that the adapter is disabled in Device Management, is that the software seems
to have correctly installed the driver, but Windows couldn't detect (plug & play) the device, so
Windows didn't enable the device driver - Windows won't load a driver for a non-existent device.
Other (remote) possibilities:
(a) Wi-Fi adapter plugged into a bad USB port. - try another port.
(b) there's a little corrosion on USB contacts of USB port or WNA3100. Try plugging adapter
in and out of the port a few times (this shines up the contacts a bit).
(c) there's a slight misalignment of contacts within the USB connector or either the laptop, or
the WNA3100.
Your fix may be returning the NetGear WNA3100 to the retailer for an exchange.

first download the latest driver if it dont work check it on other system if it works then check ur port and ifit also dont works call ur customercare

Hi,
I Would guess, that windows is leaving the handeling of the wireless connection to the NETGEAR software, and therefor not registering the device ad connected.
To make Windows regain controle take a look at this: http://www.bukisa.com/articles/115878_how-to-let-windows-configure-your-wireless-network-connection-in-xp

Click on the link below and follow instructions.

http://kb.netgear.com/app/answers/detail/a_id/17393

Try connecting direct to USB port without extension cable. Disable anti-virus software temporarily while installing drivers.

If the resource CD does not work then I would recommend you to download the installation software for the adapter from the below link:

http://kb.netgear.com/app/answers/detail/a_id/17393

Install the adapter using the software available on the link above.

I hope this information allows you to resolve this issue.

Regards

Anand

could spread some toothpaste on the cd, wipe it off then try the install again. used to work for me when i had scratched cd's