Microsoft Windows 7 does not come with tool to mount ISO image, otherwise there is a free tool that have a function to mount ISO image. We recommend using Alcohol52 from AlcoholSoft that we can download and use for free from here or from Alcohol website.
After finished downloading the Alcholol52, double click Alcohol52_FE_220.127.116.113.exe file to run the installation and follow the instruction until it finish. If you Alcohol52, you will see that you have virtual drive for your computer and with this virtual drive you can mount ISO image. Right click on your virtual drive and choose Mount Image and browse your ISO file and you will see the action like you put CD/DVD to your physical drive. Another option is by open windows explorer, that you will see that you have additional drive, right click on your drive and choose Mount Image and Open to browse the ISO image.
Beside the ability to mount ISO image, this free software has ability to mount many images file type and can make an image file. The reason why we recommend this software because of Alcohol52 is the free version of Alcohol120 and can running good in Windows 7. Hope after you know Alcohol52 will make you comfortable with your computer.