I have discovered the solution to my LAN communication problem, also uncovered a condition that I am learning to live with.....

SOLUTION)  I recently had installed a new Internet security system that replaced a previous security suite that has been shown to cause significant issues with Win7.  However, this new system has a option buried deep within its bowels that must be selected to define the attached LAN as a "Trusted Network".  Without this setting, no system connected to a LAN can communicate with any other system connected to the same LAN.  Having made the proper selection on every system, all systems now are communicating correctly with each other.

CONDITION) I also have come to learn that the Control Panel, Network & Sharing "See Full Map" feature is flaky at best.  While it may have produced a correct LAN map shortly after each Win7 system was connected to the LAN, the feature becomes unpredictable on all systems as after-market applications are installed onto one or more of the systems.  Apparently all it takes is for one application to be installed on only one system for the "See Full Map" feature to die on all systems connected to the LAN.  From what I can determine, nobody has a clue what causes this, not even the folks on various Windows supported forums and blogs.  I should add that every after-market application that I installed was certified by Microsoft as being fully compatible with Win7.

I am convinced that modern computers have become so complex that nobody understands them, not even their chief architects...scary, ain't it.  :emotion-8:

 Hytec,

You said...

I recently had installed a new Internet security system that replaced a previous security suite that has been shown to cause significant issues with

Questions are...

What type of virus protection and firewalls are you using?

Windows 7, did your computer come with Windows 7 (32-bit or 64-bit?) or did you upgrade/install Windows 7 on this computer?

Rick

The system is an XPS-17 (L701X) that was delivered with Win7(64) Premium Home.  I had installed ZoneLabs Security Suite 2010 after uninstalling the McAfee trial version delivered with the system.  I had used ZSS successully for many years with WinXP SP3, so saw no reason not use it with Win7(64).

After about 2 months the system started getting the BSOD randomly, sometimes every few hours, other times going two or three days between.  The error code was STOP 0x0000007F (UNEXPECTED_KERNEL_MODE_TRAP) every time.  Every failure until the final one caused the local LCD to become blank, however an HDTV connected by an HDMI cable displayed the BSOD.  Analyzing the memory dumps showed that NETIO.SYS had shut the system down due to the same security conflict in every case.  However the final failure did not cause a BSOD, but caused the Intel Centrino Advanced-N 6200 wireless card to "disappear" from Win7's radar.  By that I mean, regardless of what technique I used to try to access the card, Device Manager, Diagnostics, etc., the card did not exist on the system.  Interestingly the wireless router recognized the card, but could not get it to accept an IP address.  This condition was solved by recovering the system back to its as-delivered state.

From researching http://social.answers.microsoft.com/Forums/en-US/category/windows7, I found that ZoneLab Security Suite had been causing this condition with Win7 for some time, though nobody seems to know why, or how to solve it.  Needless to say, I did not re-install ZSS.

I have installed Kaspersky Internet Security 2011, and am comfortable with it thus far.  From what I read, Win7(64) does not appear to have any issues with KIS 2011.  It's too soon for me to have much experience, but it appears to be well designed based on the thoroughness of its setup options.

 Hytec,

I know that some virus programs and firewalls block communications. There have been some recently that block the wireless adapters from communicating. Some of these have since fixed the issues but there are still some virus programs that are disabling programs from working properly. I had issues with Zone Alarm not allowing us to get online, used system restore and was able to get online. With Vista/Windows 7, Windows firewall is what I have working for me. I use FREE Avast Home Edition for my virus protection and have not had any issues. I did have a free license for Avast but my computer was stolen, so I did not really get a chance to try out this feature for long. I cannot talk for all virus programs but some are resource hogs and make the computer run slowly. When you removed McAfee, did you also use the McAfee Removal Tool?

Rick

Hi Rick,

I used Win7 to uninstall both the McAfee programs which appeared to work well.  Then I used CCleaner to clean the Registry, hopefully finishing the job.

Computers have become so complex that I don't believe any one "protection" system can cover all bases.  Then again, I don't want to install multiple specialty systems from different manufacturers because they probably will go into contention with one another and destroy whatever harmony existed in the computer when it was bought.  So, I study forums, test results, reviews, and criticisms, then make an educated (hopefully) choice.  This year Kaspersky came out on top for me, but who knows what the next generation in technology will bring.

 Hytec,

I use Avast FREE Home Edition. Love th real-time scanner

Have Malwarebytes install and do a weekly scan.

Spybot Search & Destroy, without the security and no SD or tea timer

Spyware blaster.

These programs along with using Mozilla Firefox using NoScript nave kept my computer secure.

I also use Secunia PSI to keep my computer secure.

Rick