Q: What are the minimum requirements for UDK?  A: Here are the minimum and recommended requirements... 
 Minimum: 
 Windows XP SP2, Windows Vista, or Windows 7 
 2.0+ GHz processor 
 2 GB system RAM 
 SM3-compatible video card 
 3 GB free hard drive space 
 Recommended for Content Development: 
 Windows 7 64-bit 
 2.0+ GHz multi-core processor 
 8 GB System RAM 
 NVIDIA 8000 series or higher graphics card 
 Plenty of HDD space 
 Minimum for DX11 Development: 
 Windows Vista 
 2.0+ GHz processor 
 2 GB system RAM 
 DX11 Graphics Card: 
 Nvidia: 400 series or above 
 ATI: 5000 series or above 
 3 GB Free hard drive space