Download the Stand-alone GWX Control Panel found here:

http://ultimateoutsider.com/downloads/

Open the program, acknowledge the UAC prompt if it appears and accept the agreement. Then click on "Disable Windows 10 App (Remove Icon). That will blow away the annoying prompt asking you to upgrade. Then click on "Click to Delete Windows 10 Download Folders" and allow it to delete the 4 - 6GB of data for the upgrade. Then click "Click to Prevent Windows 10 Upgrades". This will change a few settings that determine if Microsoft is able to upgrade the machine to Windows 10, along with removing the ads you sometimes get when on the Windows Update screen. It will not inhibit 'regular' Windows Updates.

EDIT -> I didn't see that Crash had already posted this advice.

Shoot me a PM if you'd like some help. I'm right across the river and do IT.

I have two Macbooks in my office right now that refuse to boot. They aren't as bullet proof as people think.

I run an IT business and since the introduction of Windows 7, I've seen a sharp decline in issues. Even with the "dreaded" Windows 8 there weren't a ton of problems. Windows 10 has a lot of promise, but there are still a few issues that need ironed out. They aren't show stoppers, but stupid things like clock synchronization, time to standby calculations, etc.

Every time I use a Mac, I feel like I'm just along for the ride. It's just so annoying to use....and I own a MacBook Air. The funny thing is that almost all my clients that have Mac based businesses, run Windows 7 as a virtual machine.

Call Microsoft. 99% of the time they will give you a key if you explain the situation.

I thought that was in beta still?