Windows XP would not allow me to map a network drive claiming that i did not have permissions and that the drive would not be mapped as there "is a duplicate computer name on the network".
This is not fun but its required. Remember to ALWYAS make backups of your systems and or registry before editing them! I am providing this information with NO WARRENTY as it is what worked for me. I cannot grantee it will work for you and will not damage your system. That said, lets continue.
1. You will need to log into the server you are trying to connect to.
2. Go to "Start -> Run" and type in "regedit" hit [enter]
3. Make your backup of your registry. (File -> Export). Make sure its to a safe place.
4. Open notepad.exe "Start-> Run" type "notepad.exe" hit [enter]
5. paste the following into the new notepad. Be careful that the formatting dose not get all messed up.
6. Once you have done this. Save the file as a .reg file to your desktop. (File -> save as). Make sure that the file type is set to "All files". Make sure the file name is "FixFileShare.reg" or something similar.
7. Double click on the .reg file you just created. This will insert the new value for "DisableStrictNameChecking" into your systems registry.
8. Restart the "Server" service. (Right click on My Computer -> Manage).
Once on the management window look for "Services" on the left side. Highlight it and look for "Server" on the right side under the services. Once selected right click and select "Restart".
9. You should now be able to connect to this systems file share again without issues.
I will note that most of the above information came from here.