I have four boot images for W7. 2x OEM Pro; 2x Retail Pro. One each on DVD, one each on USB boot stick. 2x CoA. Keys checked with pidgen.exe - there are valid. All copies of W7, DVD & USB, install fine up to ' Accept Licence Terms ' page. At this point the Keyboard & Mouse, previously working, just freeze. I cannot progress the install. I do not have a firm grasp of how UEFI differs from Bios. I can't see the benefits of GPT over MBR. Do I need to resort to diskpart to format sections of install media or target SSD as part MBR and part GPT ? My build is a new Z97 Asrock Extreme 6 with latest UEFI at P2.30. The build has new HW - 2 x Samsung SSD, 1x HDD, 1x Opt. 16Gb and currently onboard graphics. I have used Rufus 2.2 to create bootable USB drives but due to conflicting advice on forums have no idea whether I'm doing this right. There is no Legacy Bios setting in UEFI P2.30 only a Compatibility Mode - CSM. Following different threads I have tried inserting two modified files into the W7 'sources' folder; I'm not sure these actions made any difference. PID.txt - this file has the Product Key of the respective image. ei.cfg - this file records the version to report to install process. Upon reflection - I'm not sure i should not have used the ei.cfg removal tool so i could choose a version at install time. I would appreciate advice from anyone who has trodden this path before or has an insight into my stupidity. Having then installed the OS...I can then worry about activation.