Windows 7: Share to some, deny to others, how do I do it?

Hey everyone, I am new to the forum here, and I have done some searching on my particular issue. Here's what I have:

1x Win 7 Pro SP1 desktop
2x win 7 Home Premium SP1 Laptops (Dell XPS)

I have a neighbor that I am allowing on my wifi network (he's paying me for it), and I want to share my hard drives between my computers without allowing him access. I already know the process on how to share folders and hard drives...and I know how to setup homegroup and workgroups. I have tried to deny him in the permissions section when sharing, but when I click the "check names" button, windows says that the name is invalid. Is there a way to do this?

Oh...I have also tried to change the name of my workgroup, but everyone still has access to the shared drives and folders. Any help on this would be great.

Thanks,

Phil

Use the firewall, Luke!

You can set up the firewalls on your PCs to stop any packets / connections from and to his IP address.
Also, you can enable password protected sharing.

Firewalls? Are you refering to using like a DMZ? I'll look into it...thanks.

(No no no! Not DMZ. Use the firewalls on your PCs. Have you ever configured a firewall? If not, I'll write a short guide.)

But, to keep things simple. Set up passwords for your user accounts on both PCs and then go to Network and Sharing Center, click Advanced sharing settings and enable Password protected sharing. That way, only the people that know user accounts + passwords on the PCs will be able to access the shared files. Those who don't know them will not be able to access the files.

The password solution would seem to make a lot of sense, but I've tried it on Home Premium, even with cloned accounts across machines, and switching passwords on does not bring up the challenge dialog, it brings up the access denied dialog. I find it completely illogical, and what should be a good solution doesn't work at all. It's either wide open sharing or none at all.

Yeah...that is what I am finding out. Although, a co-worker chimed in and said I should just used the guest account on my router, that will give him internet and separate him from the network.