I need help with transfering models and characters from Blender 2.45 to 2.58

I just recently uploaded Blender 2.58 onto my computer, but I have done a few projects on Blender 2.45 and I want to know, is it possible to transfer models and characters from an old version of Blender to the newer one? How can I do it?

Just open the blend file in blender 2.58. If there are any animations they may not work. There is no harm opening them and see if they are still ok. When you open the file deselect the ‘Load UI’ option in the blender file browser so it doesn’t use the old blender window layout.