Solved
MathCad Express
I'm using MathCad Express but it has me on a trial version. Trying to remove the watermark across the sheet.
I'm assuming you've already gone through the 30-day trial of full functionality without the watermark being present first. (What we refer to as "the 30-day trial")
If you haven't, you need to get a trial licence through the wizard.

If you've already gone through those 30 days, then you need to buy a full licence to get rid of the watermark.
Enter your E-mail address. We'll send you an e-mail with instructions to reset your password.