Although there are a lot advanced features available, burning an ISO to disc is easy.
Download and install ImgBurn (link below) taking the defaults in the install wizard.
ImgBurn opens up with the source and destination fields already filled in.
you might leave the default prefs, then tap the Write button.
That is all there is to it…click Ok and close out of ImgBurn.
Use ISO Recorder
ISO Recorder (link below) is another great utility for burning ISO images to disc.
They have a version for XP, Vista, and Windows 7 (32 & 64-bit Versions).
In the next screen the image file path is in the Source Image file field.
Under Recorder go for the drive with your blank disc, select a recording speed and click Next.
Conclusion
You don’t need an expensive commercial tool to burn an ISO image to disc.
Using any one of these free utilities will get the job done quite nicely.
Download ImgBurn from Ninite
Download ISO Recorder