I need to create the same image of D: drive on a new ultrabook. This is Windows 8.1. It has 256 GB. I created a VHD of 120 GB. It is still creating the virtual disk. I was just wondering if the size can have an impact on performance. The goal is to be able to continue to work with a D: drive such as before on all other PC and laptops I have been using for years. I only keep the C: for the installations and OS.