You can get a 3 prong to 2 prong converter for the Laptops, I know, from Radioshack that works great. I am not sure how it would work with the Portable type PC, but I use one on my Laptop, and it makes a night and day difference.
Here is the Link to the Radio Shack page:
http://www.radioshack.com/product.as...t%5Fid=61-2720