Compared to Linux-based devices, NAS boxes using Windows OS are pretty thin on the ground. One company that has kept the Windows flag flying with a range of devices is Thecus. The Thecus Windows Storage Server range is split into two camps, Large Business and SMB/Home, and it's from the latter one that the 5-bay W5810 is the current flagship model.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips