I can't seem to figure out how to load a pictureBox image from a bitmap in memory. Is it possible or do I have to create temp file for the bitmap?
What format is the image in memory?
If you have an actual Bitmap object, just assign it to the PictureBox, as suggested by dtb:
pictureBox.Image = bitmap;
If you have the image as a series of bytes held in a stream, you'll need to load the image from the stream:
var image = Image.FromStream(stream);
pictureBox.Image = image;
If you instead have a windows GDI handle to the bitmap, use
var image = Image.FromHbitmap(handle);
pictureBox.Image = image;
Essentially, it's hard to answer your question with more than suggestions when you haven't told us what format the Bitmap you have is held in.