This is a common problem when your using a design application on your local PC. While it's a little different depending on which application your using, it usually happens when you are prompted to select an image to insert. Then you start hunting all over your PC directories for the image. This can often confuse the application, because it can't create a relative link to your image source, so it puts in the full path.
You should be creating your web pages in a local folder on your PC. And, all of the images and other pages, should be in that same folder. It's common to create a "images" sub folder, in your design folder, to store all your images. This helps keep your web site neater and easier to manage. Then when you are selecting a image source, your only searching relative to your design folder and your application can create a relative link. This should create links and image references that are usable locally and on your web site, without any changes.
I recommend that you create a folder for your web pages and copy in all the images you will need. The open up your web pages and modify the image references. You could do a global search and replace using a text editor, but with most applications you can pull up the "properties" for each of your images. Then you can adjust the image reference and point it to the local folder. This may be tedious to fix after the fact, especially if you have a lot of image references, but it's not very difficult.
Most applications also have a built in upload capability. You can usually specify whether you want your images to be uploaded as well as your HTML pages. And you can often specify the destination folder for the images. Just make it match what your are using in your PC folder.
