Windows 7 is connected to my home network via a router. Everything has been working fine until this morning. Woke the computer from sleep, started the XP computer on the network and it can't see it. When troubleshooting I found that the system time was 2 hours slow. Corrected that and rebooted but still can't see the other computer. Tried in Vista (dual boot) and that was OK. Tried rebooting both the Windows 7 PC and the XP PC also tried all the various fault finding routines but to no avail. What steps should I try next

I seem to have connected again - I don't know what the problem was. However it may be due to the fact that when I try to create a network map it sees the XP computer but states The followed discovered device(s) can not be placed in the map Reason being XP SP3 hasn't got LLTD responder installed - will need to do it manually.

Hi,You can download Link Layer Topology Discovery (LLTD) Responder (KB922120) from the link belowLink Layer Topology Discovery (LLTD) Responder (KB922120)After installing the update, please restart the Windows XP machine and check whether the connection will be lost.Thanks,Novak

Thanks - the install doesn't work. This is a known problem which was why I needed to do it manually as follows - and I can now see the map and I haven't had the problem since. After installing SP3 or when you do a fresh install of XP SP3, even though the protocol won't self install you can install it youself by first extracting the files from the windowsXP-KB922120-v5-ENU.exe file. See this article. http://support.microsoft.com/kb/828030 In the folder where you extract to you will find a folder SP2QFE. Open this and you will find the required files. Then copy the rspndr.sys to C:\Windows\System32\Drivers folder, rspndr.exe to C:\Windows\System32 folder. rspndr.inf (inside ip folder) to C:\Windows\Inf folder Then open a Command prompt and navigate to the C:\Windows\System32 folder and type rspndr.exe -i This will install the LLTD responder.