Is the photo linked back to a photo imaging account? Something like Photobucket or Image Shack?

Thanks shboom for the response, yes the photos were posted on the auction site through Irfanview. I use that site to decrease the pixil size to the required amount (size) that the auction site will take. It is the first time I have done it, so there may be an easy fix, right now I just don't know what that is. I have checked/changed all my internet setting in the tools section of Internet Explorer. and decreased the security setting from med-high to med.
I don't know where to find the firewall, I have the free computer virus checks - AVG - ADWARE - CCLEANER - SPYBOT.

Irfanview doesn't work for this. You can change size, colors, brightness, etc., but you need a URL for the picture to have it to show. In other words, the picture has to be posted on the web. Many internet service providers offer free web space where you can upload your pictures. Check to see if yours does. Otherwise you can, as mentioned above, use a site like Photobucket. Once you have your picture uploaded, you right click on it, scroll down, and click on Properties. This will show the URL. Then, right click again, scroll down, and click on Select All. This will highlight the URL (web address of the picture) Then right click again, scroll down and click Copy. Then Paste this into your auction posting.

If we knew where the site is with the X, we could check the source of the picture to see what went wrong.
Irfanview is great for resizing photos, but I don't think you can post photos to the internet from it. Some sites you can upload a photo from your computer to the site, but most places need an online photo storage site that you can hot link to the url of the photo. The X most likely means there is no photo there.
I would start out by getting a free Photobucket account and upload the photo to photobucket.
After that we can tell you how to copy the html tag line to post your photos online.

If the auction site is eBay, I don't think the photos need to be on the internet to be posted. I don't upload mine, just select them from my pictures and they show up. I think once there was a problem with posting them, and clearing the cache solved it, even though the cache wasn't full.

Lotodig... as the others have noted Irfanview is an imaging tool used for making changes to your photos. In order to be able to actually post pictures, they have to be stored on the web. I use Photobucket that the poster above supplied the link for you. There is also another way if the site you are posting pictures to has the ability to upload photos from a folder on your hard drive.

Bob

Sorry I haven't responded sooner, just wanted to tell you guys that with what you've told me and I was able to figure it out. Thanks for the help........