I need a distro for a friend
 

So here's the deal:

My friend is PC illiterate, and is just starting to learn Win XP. Now I want to give this person a Linux distro since the grand kids can't install much that will slow down the system in linux and they don't really know their way around it.

What distro would be best in the sense of resemblance to Windows's atmosphere? I was thinking between Arch, Ubuntu, purely Debian. Any sujestions?

I think that are quite a few distros you can choose from.
I don't know Arch, but have seen Ubuntu and Debian.

For a user that doesn't know his way around I guess Ubuntu might be the easier choice.
In addition to those you may also consider Fedora or OpenSuse, which are also pretty easy to use.

Personally I like Fedora, because it is, in my opinion, the most cutting edge distro out there.

All of the distros you mentioned bring a lot of software (although I can't confirm this for Arch, but I just guess it does too), so you more or less just have to decide how recent you want the packages to be.

I like Debian, but for me it's not really a desktop-system, as it's already sort of outdated on release.

I would give Mint a try. Its even easier than the Ubuntu variety and looks nicer to.