I have a machine that I am wanting to revert back to Win7 from Win 8.1 I have formatted and switched between the 2 twice each time going back two 8.1 for several reasons. One of which has been the slower HDD performance I am experiencing in Win 7. I have run DiskMark on both OS(s) and have experienced the following: Win 7 Avg(4 runs) seq read 149 / seq write 143 Win 8.1 Avg(4 runs) seq read 198 / seq write 183 In both cases I have started with clean installs, formatting the volume(s) each time. For Win7 I have to install the Intel Chipset drivers to gain USB3 support, so I also go ahead and install the whole chipset package. (On Dell's website the files are separated out). I am using [murphy78 presents Windows 7 AIO 24in1 SP1 x64]. From this I am using Win7 Ultimate (OEM activated) For the Win8 install I do not have to install any additional drivers. I use the Dell OS disc that came with the machine. This OS disc installs Win 8 Home Premium. Once it is patched, I upgrade to 8.1 Any assistance would be appreciated. I really want to move back to Win 7 permanently. PC Specs: Dell XPS 8500 Intel Core i7 3770 16 GB RAM 1(2 TB) HD - [ST2000DM001] - Accelerated using Intel RST and 32GB mSata drive.