a developer's notes – a semi-technical web development BLOG

March 30, 2014

Can’t Connect to SqlServer 2012 LocalDB

Filed under: SQL — Duy Nguyen @ 11:12 am
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I had trouble connecting my sql server to (LocalDB)\v11.0 with my Windows account. I ended up having to delete it and recreate it.

Open a cmd prompt

c:\sqllocaldb delete "v11.0"
LocalDB instance "v11.0" deleted.

c:\sqllocaldb create "v11.0"
LocalDB instance "v11.0" created with version 11.0

If the database is in use, stop MSSQL service and try again.

June 25, 2012

Unable to switch Sync Profiles in Xmarks with Firefox

Filed under: Daily Computing — Duy Nguyen @ 10:17 am
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When you try to switch profiles with Xmarks, the drop down menu is grayed and is disabled.

1. With Firefox, disable the Xmarks add-on.
2. Restart browser
3. Enable Xmarks add-on
4. Try again.

June 20, 2012

Can’t connect to FTP server with External IP address on Verizon Fios with an Actiontec MI424WR router

Filed under: Daily Computing — Duy Nguyen @ 8:56 pm
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Unable to connect to a FTP site that is hosted on a PC, using the external IP Address. I am prompted with a authentication dialog box, but after you enter in the credentials, the web browser indicates that it is unable to connect.

1. Port forwarding on the Verizon Router has been configured to forward port 21 (TCP) to desktop
2. Internal IP address works
3. Using the external ip ftp://xx.xxx.xx.xx, prompts for credentials. After using the same credentials to log in, I get the following error:

IE: Internet Explorer cannot display the webpage

After speaking with an Actiontec rep, they told me the issue is that the MI424WR router does not support “loopback”. In other words, the router expects connections to the public
IP only from the external interface. It will ignore and drop traffic to the public IP from the internal interfaces, thus when you are attempting to access your machine with a public IP from within your LAN, the public IP is causing the local machine to contact the default gateway (your router) and your router is not forwarding that traffic back to your host machine.

When the tech attempted to connect to my FTP site with my external IP, he entered the ftp account and password and got right in. Basically, you can’t test this from within your home network, because of the non-loopback support. You will have to ask a friend or neighbor to test it for you. Or connect to another network OUTSIDE YOUR NETWORK to test.

I didn’t have this issue with Comcast, because Comcast only supplies you with a modem. I was using my own router. With Verizon Fios, they supply you with a router/modem in one device. So their router is made differently.

June 5, 2012

Error when you remove an assembly from the Global Assembly Cache (GAC)

Filed under: General Tips — Duy Nguyen @ 9:16 am
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When you try to remove an assembly from the Global Assembly Cache (GAC) or C:\Windows\assembly, you get this error:

Unable to uninstall: assembly is required by one or more applications

You need to delete the registry entries first at:


May 17, 2012

Creating a Windows Image Backup Fails on external 3TB Hard Drive

Filed under: Daily Computing — Duy Nguyen @ 11:23 pm
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I bought a brand new Seagate Expansion 3TB hard drive today! I was trying to back up my Windows 7 Hard Drive by creating a system image. But I got the following error:

“The request could not be performed because of an I/O device error. (0x8007045D)”

Could it be my drive is faulty? I ran check disk and it was ok. After a little research, this the problem:

New HDs have 4k bytes per section as opposed to the traditional 512 per sector.

Microsoft won’t be supporting this new hard drive formats for Windows 7 or Windows 2008.

“SBS 2011 is based on Windows 2008 R2 Server. Backup uses VHD (Virtual hard disk) format to store the data. The 4k Sector support is not available for VHD in Windows 2008 & R2 (VHD cannot be created on 4k sector size disks). Hence backup cannot provide support for 4k disks. In Windows 8, a new VHDX format is created that supports > 2 TB data storage and 4k sector disks. Therefore only in Win8 the backup is supporting 4k sector disks. When the Win8 based SBS systems will be launched then you can expect support for 4k.”

Western Digital has a utility that changes the Bytes per sector size on the 4k/4k drives so that it works for Windows Backup (will disable XP access). There is currently not a utility available for Seagate drives :/

I guess we will have to wait until Windows 8.

September 29, 2011

Why can’t I run my .NET 4.0 site on Windows 2003 with IIS 6?

Filed under: ASP.NET — Duy Nguyen @ 10:44 pm
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IIS 6 (that comes with Windows 2003) does not let you have more than one framework at a time running in the same instance like IIS7 that can create Application PoolS targeting different frameworks. This just means a single application pool can’t be used for two different frameworks like IIS7.

You have a two options:

  1. Downgrade the .NET application to 3.5 with Visual Studio 2010. Just go to the Website project properties, Application tab and there is a drop down with all the framework releases, select 3.5.

    VS2010 will reload the project and modify the web.config. If you added A web service reference, thEN you may have to delete them and re-add them under 3.5

  2. Configure IIS6 with a second application pool and a second web site.

    • Create a new application pool…

      and new web site…

      Then assign this application pool to the Framework 4 web application that will be hosted by your new site. To assign the application pool, in the IIS console open the properties section of the web application, and click on the “Home directory” tab and select the application pool which you have created earlier.

    • Then you need to change the ASP.NET version of your application. Right click your virtual directory that hosts your application and click the property and check the ASP.Net. Select Framework 4.

    • Select ASP.NET 4.0 on IIS6 under Web Service Extension. Go to the IIS6 console open “web service extension node” which is right below the “default website” node. You will see the entire ASP.Net framework list that is installed. By default these frameworks might be prohibited so please select ASP.Net Framework 4 and click allow button.

      *If you don’t see ASP.NET 4.0, make sure the framework is installed on the server! If it is, then open a command prompt go to this directory: C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319
      Then run this command: aspnet_regiis -i

      You will now see ASP.NET 4.0. If you don’t set ASP.NET 4.0 to ALLOW, You will get a “404 Page is not found.”

Check out this great article:


September 5, 2011

Killing a Windows Service that seems to hang on “Stopping”

Filed under: Daily Computing,General Tips — Duy Nguyen @ 1:13 pm
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1. Go to the command-prompt and query the service (e.g. the SMTP service) by using sc:
sc queryex SMTPSvc

2. This will give you the following information:

TYPE               : 20  WIN32_SHARE_PROCESS
STATE              : 4  RUNNING
WIN32_EXIT_CODE    : 0  (0x0)
CHECKPOINT         : 0x0
WAIT_HINT          : 0x0
PID                : 388
FLAGS              :

3.  Find the process identifier (PID) and kill the process with “taskkill”:

taskkill /PID 388 /F

where the /F flag is needed to force the process kill (first try without the flag).

Taken from http://bartdesmet.net/blogs/bart/archive/2004/10/16/438.aspx

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