@ Jake: You misread the question:
The question was, "Is there a way of converting from a bitmap to an EPS file in Windows?
This is not possible with IrfanView as far as I know. IrfanView can open some EPS files and convert them to bitmaps. It can only read the preview image if the EPS contains one. It cannot convert the EPS data to a bitmap. To convert bitmaps to EPS images you need a program that can autotrace such as CorelDraw or Serif™ DrawPlus. If the bitmap is complex, results are often disappointing.
Try
Vector Magic for this task.
The attached image was converted to SVG from a bitmap using the Vector Magic service while it was still free.