Burn Image context menu item missing in Windows 7

My understanding is that in Windows 7 if I right click an ISO image I should have an option Burn Image, or if I double click an ISO I should get a dialog to let me burn the image....

Not happening for me, any idea's why?

Edit: 29th April.

I do have isoburn.exe in my system32 directory, and it works just fine if I launch it manually from cmd. However I simply do not have the context menu when I right click on a iso file.

So my more specific question is, does anyone know how to simply restore this context menu item, an entry in the registry perhaps? (but where and what)

The above will work but an easier fix in Windows 7 is to go to control panel, select "default programs" then select "associate a file type or protocol with a program", this will display a list of file types, select the ".iso" file type then press the "Change Program" button, then select "Windows Disk Image Burner". If it's not in the list, browse to C:\Windows\System32\isoburn.exe. Press "OK". All done. Right clicking an iso file will now display "burn disk image".

Have you installed any other CD\DVD burning softwares? If so, it could be that they've associated themselves with ISO files. Try selecting the file, then right clicking it, then selecting "Open With" and see if Windows Disc Image Burner is one of the selections. If it is, just select it as the default program to open ISO files with with.