The RAM memory is expandable and supports up to 64 GB DDR5-5600 RAM, distributed across two SO-DIMM slots. 32 GB are installed as standard, but the system can accommodate up to 64 GB RAM due to thermal limitations.

1. everything that Windows supports runs on this thing. And mega fast! 2. no idea, 1000GB is enough for me.

I don't have precise information on the number of NVMe SSD slots available for this specific model. It is advisable to consult the manufacturer's official technical specifications for precise details.

This model is a compact gaming mini PC with a built-in 1000 GB SSD. The available information does not indicate that an additional HDD can be installed. ASUS NUCs are usually very compact and usually only offer space for a single SSD, especially in gaming mini PCs like this one with GeForce RTX 4070. An additional HDD installation is therefore most likely not possible or not planned.