The Canada Revenue Agency (CRA) enforces a strict limit of 20 NETFILE returns per computer/account per year for all personal tax software. You won't be able to download two desktop products for the same year on the same device. You would need a second computer with Windows OS to install the second product.
Another option is to purchase TurboTax Desktop 20 Returns and request a refund for the two Home & Business products that you have purchased.
Thank you for choosing TurboTax.