Just a few quick check points and "Guest" Account active as well as with simple file sharing checked on the Microsoft website.
Good luck.

Turn off any firewalls for fixing it. If the firewall is the problem, then you'll have to configure it to permit access to "trusted zone" addresses. Also remember that some of the firewalls must be totally uninstalled for stopping them from disturbing your networking.

Hold the Windows key and press R, then type CMD to open a command prompt.

In the command prompt window that opens, type the subsequent commands:

PING each remote computer by IP address, and if successful, PING by name. Open a command prompt as described above and type.

PING <ip address>
or
PING <computer name>

Where:
<ip address> - is the x.x.x.x IP address
<computer name> - is the computer name

A crash to PING is almost forever a firewall configuration concern. Any crash to PING wants to be corrected before you go any beyond. Also check your Services are Started on all the PCs or not. The easiest way for finding is by checking in Control Panel, Administrative Tools, and Services.

All the services must be started, and their startup type should be automatic in computer. If a service is not running, then open its properties and check its addiction. Also verify that each of the dependencies and see which one is avoiding the service from running. Checking the event log is also a good idea here, there may be clues to what is weakening. All the computers must be in the similar workgroup for computer browsing to function it appropriately. File & Print Sharing has to be enabled on any computer you desire to share files or printers from. You also require truly sharing of the resource in question from My Computer, right clicking on the drive/printer/folder, and finally selecting the sharing option.

If you coming across the complexity of accessing the computers that are visible in Network Places, also make sure the computer is being right to use who has an account with the same name/password as the system connecting to it uses to login. While the default NetBIOS setting is accurate for normal network configurations, it's likely for it to be changed, and it costs not anything to make certain it's correct. You can also open a command prompt as illustrated over and type the subsequent command: nbtstat -n. This will exhibit the status of NetBIOS or specify it's not been configured.

Thanks’ a lot for all of the costly information. I have already shared enabled but was not conscious of the firewall which is being a feasible culprit in this problem.

I will go after the directions you have supplied and will begin by "pinging". I'll get back to you later when I finish doing it.

Thanks again.

Let us know about how you make out from my solution.

Checked svcs, facilitated "auto" on a few. WLan (vista) not on the list...I assume it since this is XP w / SP3. The other PC is also running XP w/ SP3.

Can't memorize where to check if workgroup is the similar. After the re-install I had to control it since we are not capable to connect to the internet, so now I'm connected to the wireless crossover cable directly connected to the modem. Would that be a cause why I can't shift the files back to hers?

Right click on My Computer - Properties - Computer Name tab - Workgroup is in the middle of the page. If both the computers are having internet access in the course of the router then the crossover cable is not reasoning for a problem.

Ah, ok, workgroup name is "MSHOME". I’m also unable to open the pictures folder now, error message is not available. You may not be having authorization to use this network resource. Contact your admin of server for knowing out if you are having permissions.

The network path not found.

XP Pro, right? With the help of XP Pro if easy File Sharing (Control Panel - Folder Options - View tab - check at the bottom 'make use of easy file sharing') is used Program Files, My Documents, My Pictures and some other folders cannot be contact distantly.

You can also make use of Advanced File Sharing and set the permissions on those folders for permitting the remote access.

Yep, this is XP Pro, with SP3 and also a simple file sharing is being checked. Where can I locate "advanced file share" as well as set permissions?
Thanks' a lot.