When you call DELL customer support for any help, they will ask for either Service Tag or Express Service Code. You also need service tag to download drivers and documentations from DELL support website.

When you have physical access to the system, you can easily identify the service tag affixed on the body of the server. DELL support site shows the exactly location of the service tag and express code stickers for various DELL equipments.

When you don’t have physical access to the server, you can get the same information remotely from the OS level. Using Windows or Linux command line you can easily get DELL service tag as explained below.

1. Get DELL Service Tag on remote Windows system

Login to the Windows remote-host using VNC or remote desktop connection. Use WMIC on Windows to get service tag as shown below.

C:\>wmic bios get serialnumber
SerialNumber
ABCDEF1

Following WMIC command will give make and model number along with service tag.

C:\>wmic csproduct get vendor,name,identifyingnumber
IdentifyingNumber    Name                Vendor
ABCDEF1              PowerEdge 2950      Dell Inc.

If VNC or remote desktop connection to the remote-host is not available,  execute the following from the local-host to get the service tag of the remote-host.

C:\>wmic /user:administrator /node:remote-host bios get serialnumber
SerialNumber
ABCDEF1
[Note: Replace remote-host with the machine name of your remote-host.]

2. Get DELL Service Tag on remote Linux system

Login to the Linux remote-host using SSH. Use dmidecode on Linux to get service tag as shown below.

[remote-host]# dmidecode -s system-serial-number
ABCDEF1

3. Get DELL Express Service Code From Service Tag

Service Tag is a base-36 integer.  Once you have the Service Tag, you can calculate express service code yourself. Express Service Code is base-10 decimal integer of Service Tag. Dell uses express service code mainly for their support call-routing. When you call dell support, their automated call-routing system may ask you to enter express service code, which you can easily enter in your telephone, as it is just a bunch of numbers, instead of characters.

Use the following online tools to find express service code from service tag and vice-versa.

• Creativyst Dell-Number Widget
• Dell PC service tag/code converter from PowerDog Industries

Computer on the Network with the Same Name

Use the nbtstat -n command to see the name of the computer in the conflict state. The IP address of the node that sent the message is in the data that this command returns. The following example shows what the data may look like in one of these events:

Offset 28 is the IP address of the computer requesting name release. To determine the decimal IP address, invert the four hexadecimal numbers and convert them to decimal numbers separated by periods. Using this method, the IP address of E7 1A 65 16 becomes 22.101.26.231.

The status column of the nbtstat output for the computer in conflict should contain either "Conflict" or "Released."

You can run the nbtstat -a command with the IP address to get the computer name.

Example: nbtstat -A 192.168.1.21

NBTSTAT -A May Return Host not Found Error Message 

To resolve this issue, verify that the NetBIOS Interface device is set to start either Automatically or Manually and that the Messenger service is set to start Automatically. Perform the following steps on the target computer:

1. Click the Start button, point to Settings, and then click Control Panel.
2. Double-click the Services icon, and select the Messenger service.
3. Click Startup, click Automatic, click OK, and then click Close.
4. Double-click the Devices icon in Control Panel, and select the NetBIOS Interface device.
5. Click Startup, click either Automatic or Manual, click OK, and click Close.
6. Restart the computer.

NOTE: Simply starting the NetBIOS Interface device is not sufficient. The NetBIOS Interface device must be reset by a NetBIOS application such as the Messenger service.
Source from here.