Also make sure you download the correct version of Windows 7 for your needs – to find out which edition (Home Premium, Professional or Ultimate) and type (32-bit or 64-bit) you need, click Start, right-click Computer and select Properties. This downloadable file is for Windows 7 Ultimate SP1 64-bit users. Download Windows 7 Service Pack 2 (64-bit & 32-bit) The Convenience Rollup update (ID – KB3125574) is optional for those users running up to date Windows 7 operating system on their machine. Since all the critical security updates and fixes are already installed on the computer via Windows Update, and you don’t need to install them again.

Download the corresponding edition of Windows 7 you have a license for from the following link. You can identify the edition on COA sticker attached to your machine, with at bottom or battery compartment (laptop) or top/side if its a desktop computer.

COA Certificate of Authenticity:

What is the Windows Certificate of Authenticity?

•Windows 7 Home Premium (x64) - 64 bit

32 vs 64 bit

Is my PC running the 32-bit or 64-bit version of Windows?

ImgBurn - In addtion to supporting the creation of CD's from .ISO files,
it supports a wide range of other image file formats, and it's free.
(BIN, CUE, DI, DVD, GI, IMG, MDS, NRG, PDI and ISO)
http://www.imgburn.com/

Note: Always use the slowest burn speed (4x or 2x) if offered a choice.