AE will not connect to wifi cablevision network

Unfortunately, your post did not provide any details to help us with your issue.

Is an AE an AirPort Extreme....or....is it an AirPort Express?

If the AE can be configured to connect to the wireless network......What will the AE do on the network? What service will it perform?

We don't know what device that you are using to try to set up the AE. What are you using? What operating system is it running?

Just purchased a new HP Spectre 360 with Intel Core i5

Is this the device that has AirPort Utility installed? If it is, unfortunately, Apple has not updated AirPort Utility for Windows since Windows 7, and I do not know if the older AirPort Utility version that you have will run correctly if you are running a newer version of Windows. I don't have a PC here to test.

In case the HP computer cannot be used to set up the AirPort Express, do you have an iPhone or iPad handy?

I open airport utility and plug in AE

Sorry, but not sure what "plug in" means here. Normally, if you "plug in" something, you are making a physical, wired connection. If you want to permanently wire the AirPort Express to your network, it must connect to your wireless router.....not to your computer.

Normally, most users want the AirPort Express to connect to their existing wireless network using a wireless connection.

That is why we are asking whether you plan to connect the AirPort Express wirelessly.....or wired. Can you clarify on that?

Thanks. We also asked.....

In case the HP computer cannot be used to set up the AirPort Express, do you have an iPhone or iPad handy?

Then, the iPhone would be your best bet to set up the AirPort Express.

Power up the AirPort Express for a few minutes

On the iPhone Home Screen....

Tap Settings

Tap WiFi

Look for a listing of Set Up New Base Station

Tap on AirPort Express

Follow the prompts

That is correct. You will need to be connected to same network in order to do both. That is both wireless access points must be on this "same" network in order for you to do both simultaneously.