If you are installing on a newer machine (Intel 100-series chipset or newer), the installer will likely freeze because it lacks USB 3.0 drivers
If you have an active MSDN subscription or a Volume Licensing Service Center (VLSC) account, you can download the original "Windows 7 with SP1" ISO files. Note that even these stock ISOs do not fully support UEFI out of the box for all system configurations. You will still need to modify the installation media. Windows 7 Uefi Iso Download