I want to use a laptop to download UE4; my laptop seems to meet all requirements but the fact that it is a laptop. Could I download UE4 on my laptop and would it work? My desktop is so old and messed up that it seems unrepairable and unsellable.
I have UE4 installed on a 2-3 year old laptop which I bought back then for 700 €, and it runs ok, not good, but good enough for me to not get frustrated. So if you have something similiar or better it should run fine!
Hi PresidentPorpoise,
Our minimum system requirements are posted in the Frequently Asked Questions section of our main page, UnrealEngine.com.
What are Unreal Engine 4’s system
requirements? You will need a powerful
setup to get started developing with
UE4 right now. Here’s what we
recommend: Desktop PC or Mac Windows
7 64-bit or Mac OS X 10.9.2 or later
Quad-core Intel or AMD processor, 2.5
GHz or faster NVIDIA GeForce 470 GTX
or AMD Radeon 6870 HD series card or
higher 8 GB RAM
These specifications reflect what we feel are the minimum requirements to have a good user experience using the engine.
The engine can run on slower machines in most instances but it is not guaranteed to run or to even provide a good user experience.
The community has put together a forum thread with their machine setups and what their experience is with the engine. The post is titled: [Compatibility List] Unreal 4 - Hardware Feedback]
Take a look there and see if anything matches what you are have or is close. This will give you a better idea than I could about what will best work for you.
I do want to mention as well that the engine is capable of scaling the detail down to give you a better user experience but it will lack features when this is done though. I’m linking the Engine Scalability Settings here to see if this may assist you in what you’re looking for. 
Thank you!
Tim