Unable to upload images

Hi. I am trying to upload some images to a friends WP site, but each time I try, I get this error:

“Unable to create directory D:\webs\alla25/wp-content/uploads/2011/10. Is its parent directory writable by the server?”

I believe it is a problem with where it is trying to upload the image to, specifically the part “D:\webs\alla25..” I am trying to upload from my home computer to a hosted site, so why does it have that D drive spec in there?

In the settings-> Media the upload folder is set to the default. Ideas?