Archive for the ‘Systems Administration’ Category

Dell Inspiron 1525 CD/DVD Issue

4. July 2009

No Comments »

I was recently given a Dell Inspiron 1525 to fix. The CD drive was not working. I am not going to discuss the multitude of causes or methods to troubleshoot this issue. I am simply going to provide the solution that worked for me.

1. Temporarily remove any CD burning software.

2. Edit your registry. Navigate to

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}

and delete “Upperfilters” and “Lowerfilters” values if they are present.
(http://support.microsoft.com/kb/314060)

3. Remove the CD-ROM driver from device manager.

4. Reboot the computer and reinstall the CD-ROM driver.

Multiple Firefox Profiles

29. June 2009

No Comments »

Whether you are sharing a computer with a roommate or are afraid you will screw something up while developing a Firefox extension – it is a good idea to have multiple Firefox profiles. I use one profile for general browsing, another while I’m doing web development, and another while I am doing Firefox development. Each profile has a different set of favorites and extensions installed on it. Each profile is setup for it’s particular task. Creating a profile is simple.

1. Close out of all Firefox windows
2. Open up a command prompt and type

“C:\Program Files\Mozilla Firefox\firefox.exe” –profilemanager

1_cmd
3. This will start the Firefox profile manager. Click “Create Profile…”
2_profilemanager
4. This will start the profile wizard. Click the Next button.
3_profilewizard
5. Enter your profile name. I will be using “dev” for development.
4_profilewizard
6. Your profile has been created.
5_profilemanager
7. Now you can create a shortcut on your desktop that will open up Firefox using this profile. For the item location, use:

“C:\Program Files\Mozilla Firefox\firefox.exe” -P “dev”

The -P selects the profile “dev.” Replace dev with the value you used in step 5.

Note: Only one profile can be open at a time. That is, if you open Firefox using your default profile, then click on the newly created shortcut – Firefox will open using your default profile.

Slow Network Transfer with Vista

26. June 2009

No Comments »

The Windows Vista TCP/IP stack came packed with a multitude of new features, one being Receive Window Auto-Tuning. The TCP receive window size is the amount of data that a TCP receiver allows a TCP sender to send before having to wait for an acknowledgment. After the connection is established, the receive window size is advertised in each TCP segment. Advertising the maximum amount of data that the sender can send is a receiver-side flow control mechanism that prevents the sender from sending data that the receiver cannot store. A sending host can only send at a maximum the amount of data advertised by the receiver before waiting for an acknowledgment and a receive window size update.

While the intention of this feature is to enhance user experience, this has certainly not been the case for me. Rather than improving network transfers it caped mine at 50kb/s. To disable Receive Window Auto-Tuning open up an elevated command prompt and issue the command:

netsh interface tcp set global autotuninglevel=disable