Need help reducing picture size(KB)

[Retrieval]

I've scanned a photograph of mine to use in my profile but I cant resize it, I downloaded four different programs and still couldn't do it. I tried to post it in the 'resizing AV ' thread but the 'manage attachments' box will only accept pictures of 100 KB or under when my picture is over 800 KB, so I need a way to reduce the Number of KB.
Any ideas?