Do I need to remove the CPU cooler to install RAM in a mini-ITX build?

Yes, you’ll need to take the cooler off. In a mini-ITX build with a big air cooler that hangs over the RAM slots, there’s usually no way to access the clips or slide the RAM sticks in. Removing the cooler means cleaning off old paste, applying new paste, and reseating — it’s more than a five-minute job. If you haven’t bought RAM yet, check your cooler’s clearance and buy low-profile sticks to avoid the hassle.