magnetic lasso error: too complex

I have been trying to use the magnetic lasso tool in Photoshop 7 to select part of an image. I want to extract as much detail as possible, so I have been zooming in real close and laying down a lot of anchors mapping out the image. When I am nearing completion, I get an error message saying that it is too complex to complete. Is there a way to adjust the magnetic lasso tool, so that it will stop giving me an error, or is there a better why to select a complex image?

Or use the Extract tool.

The complete error message reads “could not complete your request because the path is too complex.” I have 256 mb of ram, and 80% of it is dedicated to Photoshop. The frequency of anchor points is set to 100. I’ll try the pen tool and the Extraction filer to see if they work better.