Friday, August 17, 2007

XP Machine Can't See Vista Computer - Solution

I'm at my brother-in-law's place and had to troubleshoot a network issue.  I didn't see quite this situation on the web so I'll post it here in case it can help someone else.

The issue was that his laptop (XP) couldn't see his desktop (Vista).  The easy guess was that it was a firewall issue but I looked and the Windows firewall was disabled.  To throw a wrench in the works, my laptop (Vista) could see the desktop.  I surmised then that it couldn't be a firewall issue.  A firewall would block both clients, wouldn't it? 

After some investigation, I noticed something.  When I pinged the desktop from the Vista laptop, the ping address was IPv6.  When I did the same from the XP laptop, it was IPv4.  I tried the IPv4 address on the Vista machine and it now failed to get a response to the ping.  Very strange. 

The web didn't appear to be any help.  I tried several things none of which helped so I won't enumerate them here.  In the end, I found the culprit.  It *was* a firewall issue afterall.  The desktop happened to have McAfee SecurityCenter (v 7.2) installed which had its own firewall.  Disabling that firewall fixed the issue.  The data at hand would seem to indiate that this particular firewall only protects the IPv4 stack, however.  Oops.

 Hopefully this will help at least one of you solve a similar problem.


  1. PingBack from

  2. thanks a million, this blog saved me ROYALLY!!

  3. Had the same problem also and so I played with the program and found out you just need to add the IP of the other computer to McAfee Security Center by doing the following:
    To fix the problem go to your Security Center in McAfee. You can get there by right clicking on the red M next to the clock and select Open Security Center or go to start and select it.
    1. Click Internet & Network
    2. Click Configure (located under "To Change Your Options")
    3. Click Firewall Protection Is Enabled  
    4. Click Advanced
    5. Now go to Trusted IPs on the left and add the IP of the computer running XP on your Windows Vista computer. (vice versa)
    To find out the IP of the other computer go to that computer and go to your network connections.  Right click on the connection you're using and select status and go to the support tab.
    Charla Littlejohn (Memphis, TN)

  4. I gotta laugh at myself for this one. Seme problem and Delltech support punted me after an hour. The problem Norton Symantec (trial) was turned on along with the Windows Vista firwall. Turned off Norton (permanently) and rebooted. All systems see each other now.

  5. I just want to say that I love you Steve Rowe.  Thanks for this solution.  I can't believe I overlooked such an obvious roadblock.

  6. Glad to hear I was able to help.