If you really want Windows CE, you'll have to pay for both the developer kit and a device license from Microsoft, and they're usually expensive.
Windows CE is more properly called Windows Mobile, and there's a Mobile CE and XP versions.
Start looking here:
There's a Windows Mobile CE trial version that you can download and try before you buy.
The trial version will let your device run for a limited time, usually 30 to 90 days, and you can't get around that, it's built in.
You'll need to use the development kit to build a target image for the system you're planning to run it on, and load the image onto the hard disk.
It's complicated and expensive, but certainly possible.