Nightmare system requirements state that you will need at least 4 GB of RAM. The cheapest graphics card you can play it on is an Intel HD Family. You will need at least 200 MB of free disk space to install Nightmare. An Intel Core i5-650 CPU is required at a minimum to run Nightmare. Whereas, an Intel Core i7-920 is recommended in order to run it.
Nightmare will run on PC system with Windows 7, Windows 10 and upwards.