This would be a good time to explain image sizing. This should help a lot of people, so please do not take this as a direct lesson to you, but for everyone that has tried to post pictures. :)
In general most forums do put restrictions on image sizes and that is usually based on two factors.
1. Dimension (pixel size)
2. K Size (the space the image takes up)
Many people think that they have to reduce the pixels to control the K size which is only partly true and the reason why many people post tiny pictures.
In fact, you should be able to maintain the pixel size and reduce the K size to keep a large pixel image.
So just for an example, this forum has a restriction of 1000 pixels wide and 90k on .jpg images.
If your image is 1000 pixels wide and 260K it will not work. Many people keep cutting the image down in pixels to reduce the K to the point the image is only 125 pixels wide. So small it is hard to see what it is.
In fact many softwares will easily take the 1000 pixel wide image and let you adjust the K size to anything down to 2k. Of course the image will be very hard to see. So I usually adjust it as far down as possible without losing the clarity of the image.
With that said you can also go online and find an online sizer that will keep the image dimension, but reduce the K size for you.
Many softwares will also use the terms "Web Ready" "Optimized for the Web" So depending on your software will determine how it handles the image sizing. Also look for "Export Options" and or "Quality" when saving the image
Please let me know if and what software you have and I can probably help solve the issue.
I usually just ask people to send me the image and I can easily make the changes for you.
I hope that helps everyone.
David