I cannot see iPhone in My Computer

You install iTunes on the computer (which installs the iPhone drivers). Then connect the phone and Windows should prompt you to transfer photos. You never need to see it in My Computer, and, if you could it would be quite confusing. But Windows knows how to get the images from the iPhone.

For Windows 7 and later, use Import pictures and videos. Here are the full instructions from Windows Help:

How do I get pictures from my camera to my computer?

Here's one common way to copy pictures and video clips from your digital camera to your computer:

1. Connect the camera to your computer by using the camera's USB cable.
2. Turn on the camera.
3. In the AutoPlay dialog box that appears, click Import pictures and videos using Windows.
4. (Optional) To tag the pictures, type a tag name in the Tag these pictures (optional) box.
5. By default, the folder name includes the date the pictures and videos are imported and the tag name.
6. Click Import.
7. A new window opens and shows the imported pictures and videos.