Windows 7 on the ground is free or you will have to pay $600.00.Windows 7 Enterprise can be downloaded or compiled into an ISO as a "day-to-day trial" version. The second thing you need to do is make sure that a USB flash drive,DVD, and ISO file are all connected. A USB/DVD Download Tool will give you four simple steps that you can easily perform after getting the ISO file downloading. Once you have started the Tool, choose Tools from the list to start the Tool. Using your DVD drive or USB port, insert a bootable DVD or USB device and reboot your computer after doing that, you need to change the BIOS settings back to "C:/" in the first DVD drive or USB device to which you wish to insert the bootable DVD or USB device.