Setting up network bt Seven and Vista

First off, I am VERY new to networking, so you can't over explain anything to me.

I am trying to set up a network between a Windows 7 PC (call it PC-1) and a Windows Vista PC (call it PC-2).

PC-1 has a backup drive, which is backed up nightly. So I want to have a folder on this PC which I can access from the PC-2, so that it is still backed up each night.

I Googled how to do this, and I found out how to create the Shared Folders between the two. Couple issues with this. PC-1 can see a shared folder on PC-2, which is ok if it has to be that way, but I'm just trying to avoid confusion, and would like a single shared location.

The other issue is this. If I have a txt file in the shared folder on PC-1, and it's open, and I then try to open it from PC-2, it opens with no problems, but not as read-only. So PC-2 is not alerted that PC-1 has it open. And either one can then save changes, so it seems like that could be a real mess.

Is this a lot more complicated than I'm thinking???

Thanks in advance!

That is very true... but when you back things up... don't you do it late at night and have all programs closed. It is never a good idea to have anything open during a back up... especially a file that is being modified (as you modify, it will be in RAM) and copied (copies the file from hard drive) at the same time. You will run into that problem.

So nothing is changed to the file until you hit save; theoretically, moves the data from ram and puts it on the hard drive.

Maybe I confused this with the whole backup thing. I was just pointing out that I'd like my "master" files, or the shared drive/folder to reside on PC-1, since it is being backed up. I'm not referring to something happening during the backup process.

I just want to know how to create a network drive, or shared folder, or whatever you want to call it, so I can accomplish my goal. The way it is now, both PCs can have the same file open on the PC-1 shared folder. Whoever saves it, saves it. So PC-1 could save some changes, not knowing that PC-2 has it open at the same time. So PC-1 closes the file, thinking their changes were saved, but since PC-2 is going to save it last, it's their changes that will be saved, and PC-1 changes will be lost.

I just want it to say that the file is already open, so it can only be opened in read-only. How do I achieve that???

Yeah I can tell you how to tell you to keep all files in READ ONLY (Sharing Options), but the thing that will bogg me is having the Computer 2 being able save the file if Computer 1 is not using the file.