sharing files on a win7 machine with XP machines

When I share a folder from my windows 7 machine, my XP machines are unable to access those folders; I get NOT ACCESSIBLE errors, the only folder that works is USERS, which isn't a whole lot of use to me, as all my data is on another drive. The windows 7 machine is able to see all shared files and folders on the XP machines. All computers are connected to the same work group, and I tried giving shared folders the same exact settings as Users, but to no avail. I've even shut off windows firewall and it still doesn't work.

Try this:

Share Files and Printers between Windows 7 and XP :: the How-To Geek

I did. That guide allows \users\public to be shared, but says nothing about sharing folders that are not in \users\public

It shouldn't matter. They just used it as an example. As long as file sharing is on, go through the screens when you right click on the HD or folder you want to share and allow full access to everyone.

Similar thread:

XP cannot share with Win 7

If your Win7 PC can see inside the XP machines, why not use the Win7 Computer to transfer the data you want to the XP machine, rather than using the XP machine to browse for what you want to transfer?

Because, perhaps, I want to watch a video file that is stored on my windows 7 machine on my laptop, which has a much nicer screen, without transferring it over?

Fair enough. Why not place the video in the folder that you CAN access?

Drive space. The only folder that can be viewed by other machines on the network is on the C drive, and my C drive isn't that big. It has space for windows and the programs I use on a daily basis, but not space for videos. I'd have to constantly cycle stuff through the shared directory, which is a bit of a pain to do.
If I could put the \users\public folder someplace else, and have it still work, that would fix my problem

This is a VERY long shot, but perhaps, in the \users\public folder (whichever folder the XP machine can see on your Win7 machine), create a shortcut to your other drive. Im not 100% this will work, but its worth a try, right?