Converting bitmap to 8-bit ....

I need to be able to be sure that when I save the image in a picturebox that I'm saving it as an 8-bit bitmap. How do I convert it, or do I need to?

[parksie]

Does it HAVE to be 8-bit, or just readable by something specific?

I need to save the bitmap as 256 color. I'm working on a tileset assembly program for a CRPG creation package (www.runesword.com) and the software will only work with 256 color bitmap tilesets.