ASPX Programs Throwing Errors on Windows 7


I have an intermittent issue with some Windows 7.0 machines.
We are still running 2003 SBS until the upgrade finishes.

Users go into the Companyweb to get to ASPX applications.
Getting into the Companyweb has no problems.

When some W7 users click on certain ASPX application it errors saying there is a "Server Error in '/XXXXXX' Application.
That usually means a programming error.

The same ASPX application works fine on an XP machine using IE8, Firefox and Chrome.
Clicking on a list of individual links (in an email) on a W7 machine some work and some don't.

This issue started for one machine after a Windows Update on 11/11.
Whether it is because of the update or something more basic I have yet to determine.

In a program that fails, I have a block of code that looks for the machine IP address and machine name.
I use this for activity audit trails and username look ups.

It seems that the machine name on the W7 machines do not include the domain name like it does on XP.
In XP the IP would be and the machine name is Computer1.Domainname.local.
In W7 (after the update?) the IP would be and the machine name is Computer1.

I have a code fix.
I can go through all the programs at a great expense of time and effort to modify the code. I don't want to.
Does anyone know of where the issue comes from and how to fix it?


Code showing the offending difference:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@ Page Language="VB" Debug="true" %>
<%@Import Namespace="System.Net.DNS" %>
 <script runat="server">

Sub Page_Load
	Dim host As System.Net.IPHostEntry
	host = System.Net.Dns.GetHostByAddress (Context.Request.ServerVariables.Item ("REMOTE_HOST"))
	dim machineName as string = host.HostName

  	lblBrowser.Text = Request.Browser.Browser & " " & Request.Browser.Type & "(" & Request.ServerVariables("remote_addr") & "::" & Left$(machineName, machineName.IndexOf(".")) & ")" 

=== machineName.IndexOf(".") is where it fails - No '.' Domain name in machine name

Open in new window

Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

There are several issues with the KB3097877  updates dated from 11/10, users reported about Outlook crashes and crashes of other appliations and black sceens after logon and issues with touch screens

KB3097887 was fist published on 11/10 and after a lot of complains they rebublished it for Win7, Win7-64 and Win 2008 R2 with the date 11/12 under the same KB article.

You may try to uninstall this update to see, if it is also responsible for this issue.
As ASP files are running on the server, investigate the server as well.
Bob_ETAuthor Commented:
Thanks for the response Bembi.
I'm thinking KB3097877 may not be the problem.

I have 2 Dell 780 Optiplex machines running Windows 7. Same machines.
#One has been in service for more than a month.
#Two came into service a week ago.
Both use IE11, Firefox and Chrome.
Both have update KB3097877 installed.

I'm thinking it's an update that causes a DNS issue of some sort.
When the ASPX program accesses the full name of the first machine it gets - Machine1.domain_name.local.
This instance doesn't throw an error.
With the second machine the same program only sees an abbreviated name - Machine2. No domain name.
This is where an error occurs. The code is expecting a domain name.

Not to look a gift horse in the mouth I uninstalled KB3097877 with no change in the error.
Have you had a look into the DNS, or used nslookup to resolve the IP?
If the computer shows up in a wrong way in DNS, just delete the record from DNS and reboot the machine....

You can also have a look into the machine account in AD, how the record looks like.
You can also remove the client from the domain, delete the AD record and read the machine again.

In general, the Win7 client should append its own domain suffix, I have seen sometimes, that computers registers themselves without domain name, but only if they are not member of  domain.

But id IPConfig /all showing according t the domain suffix?

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
.NET Programming

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.