You can find a number of easy, cheap "Photoshop" type packages at office supply places. Sometimes under $15

They will allow you to open BMPs and save as JPGs, do some correction and resizing. You don't need all the bells and whistles to make scans of casino chips.

I use LView which does everything I need.

The simple answer is right click on the image and whatever windows viewer that's on the computer will open the picture, then SAVE AS (just like the first answer says) a JPG. If you can find cheaper than free, it's a good deal...

The second hand scanner I have, seems to make images at 100 DPI at best, and you can see below, that's more than enough quality for the internet.