Bitcoin Point of Sale for Windows or Web browser.

I'm helping a friend set up a point of sale bitcoin service for his retail store. He simply uses a second monitor to display the invoice to customers, and I thought it would be easy to set this up to display a browser window for customers make a purchase in bitcoin. He does not want to have a second device such as an Android tablet for the display of the QR code.

Are there any bitcoin merchant services that run on Windows? I've done some looking around and I could only find Android/iOS apps with this function. Currently, my workaround for this is to use Coinbase and their browser based checkout page set wit the option "user can change the amount", however, this is a customer-side checkout designed for online purchases. The QR code displays too small for an in-store purchase, and the page needs to be set up with an amount already in the price box.

I heard that BitPay hosts a browser based POS. Is this true? I'm currently applying for an account with them to check out their services. Mostly I just need something that displays the QR code larger than the Coinbase page. It would be a plus if it didn't already need to have a price put in the price dialog box.