Hi,I have a couple of Windows XP computers and a couple of Vista computers. I share files, printers etc. and it all runs great.One of the family has been away, and now they have come back their laptop won't connect to the XP computers. It connects to the Vista (and Win7) computers just fine.It must be something wrong with the laptop, as my other Vista/Win7 computers connect fine to the XP ones perfectly.I have tried disabling firewalls.The error I get is:Windows Cannot Access \\COMPNAMEIf I click diagnose I get:"COMPNAME" is not a valid hostnameThe laptop is running Windows Vista Home 32bit with SP1, using it's wireless connection. One of the XP machines is wireless, the other is wired and both are XP Pro 32bit with SP3.Can anybody help me out please?Many thanks...

Hi, Thank you for your post. If everything worked before on the Windows Vista laptop, a quick solution is to restore the system back to the previous status when the issue didnt occur with System Restore. (Note: Performing a system restore may cause the loss of the current system settings; therefore, before doing this, please make sure that the system restore point is not too old and set a restore point for the current status.) Based on my research, I would like to suggest the following: 1. Please check if all the computers are in the same workgroup and if the computers are all in the same subnet. 2. Please ensure the firewall setting on the Windows Vista laptop are set the enable File and Printer Sharing. 3. Just as a test, you can disable the share and re-configure the sharing on the Windows XP computer and ensure that you have assigned the Full-Control permissions to Everyone on both Sharing and Security tabs of the share folders properties. Then try to access this Windows XP computer via the Windows Vista laptop. 4. This issue can also be resulted by the factor that some third party security software or firewall blocked the access between the Windows XP computer and the Windows Vista laptop. Please perform a Clean Boot to check the issue. How to troubleshoot a problem by performing a clean boot in Windows Vista http://support.microsoft.com/kb/929135 How to perform advanced clean-boot troubleshooting in Windows XP http://support.microsoft.com/kb/316434 5. Please ensure that all the updates have been applied on both computers. 6. Ping the Windows XP computer from the laptop both with IP Address and computer name to see how it works. Access Windows XP computers share with both XXX.XXX.XXX.XXX\folder to see if it works. Hope this helps. Thanks.Nicholas Li - MSFT