Top 65 Service Desk Analyst Interview Questions

1. What is Active Directory?

Active Directory (AD) authorizes and authenticates all users and computers in a Windows domain network. It manages security policies, creating admin users, and connecting to shared resources like printers and drives centrally.

2. What is DHCP and why is it used?

DHCP (Dynamic Host Configuration Protocol) automatically allocates IP addresses to devices on a network. It eliminates the need to manually configure every single computer, preventing IP conflicts and saving time.

3. What is DNS?

DNS (Domain Name System) acts as the phonebook of the internet. It translates human-readable domain names (like www.google.com) into IP addresses that computers understand (like 142.250.190.46).

4. What is the difference between Forward and Reverse Lookup?

Forward Lookup converts a Hostname to an IP address. Reverse Lookup converts an IP address to a Hostname.

5. What is the difference between a Domain and a Workgroup?

A Domain is a centralized network managed by a server (Domain Controller) where user accounts are stored centrally. A Workgroup is a peer-to-peer network where each computer manages its own user accounts and security locally.

6. How do you troubleshoot a "No Internet" issue?

1. Check physical cable connections.
2. Run ipconfig to check if the PC has a valid IP.
3. Ping the Default Gateway (Router).
4. Ping a public DNA (like 8.8.8.8) to check internet connectivity.
5. Ping a website (google.com) to check DNS resolution.

7. What is a BSOD (Blue Screen of Death)?

BSOD indicates a critical system error where Windows cannot operate safely. It is often caused by faulty hardware (RAM/HDD) or bad drivers. Troubleshooting involves rebooting, checking event logs, booting into Safe Mode, or running hardware diagnostics.

8. What is the difference between VPN and RAS?

RAS (Remote Access Server) is typically a point-to-point connection (like dial-up) connecting a user to a LAN. VPN (Virtual Private Network) connects a user securely over a public network (internet) to a private network using encryption (tunneling).

9. What is an APIPA address?

APIPA (Automatic Private IP Addressing) is a feature where Windows assigns itself an IP address (range 169.254.x.x) if it cannot reach a DHCP server. Seeing this IP usually means there is a network connectivity or DHCP server issue.

10. What is a Default Gateway?

The Default Gateway is the IP address of the router that allows devices on your local network to communicate with devices on other networks (like the Internet).

11. What is the difference between RAM and ROM?

RAM (Random Access Memory) is volatile memory used for temporary data storage while the computer is running. ROM (Read-Only Memory) is non-volatile and stores permanent instructions like the BIOS/UEFI bootloader.

12. How do you create a backup of Outlook emails?

In Outlook, go to File > Open & Export > Import/Export. Choose "Export to a file", select "Outlook Data File (.pst)", choose the folders to backup, and save the .pst file to a secure location.

13. What is Safe Mode?

Safe Mode is a diagnostic startup mode in Windows that loads only the essential drivers and services. It is used to troubleshoot issues like malware, bad drivers, or software conflicts that prevent normal booting.

14. What is a VPN server?

VPN (Virtual Private Network) is a private communications network used by organizations to communicate confidentially over a public network. It creates a secure "tunnel" that encrypts data between the user and the corporate network.

15. What is the difference between RAS and VPN?

RAS is typically a local area connection between two specific points (point-to-point), while VPN is a secure connection spread over a large public area (the internet).

16. What is an IAS server?

IAS (Internet Authentication Service) performs centralized authentication, authorization, and accounting (AAA) for network access. It validates users connecting via wireless, VPN, or dial-up.

17. User lost network connectivity: How do you troubleshoot?

1. Check physical cable connections and switch port lights.
2. Run ipconfig to check for valid IP or APIPA (169.254.x.x).
3. Ping the loopback address (127.0.0.1) to test the NIC driver.
4. Ping the Default Gateway.
5. Check proxy settings in the browser.
6. Check if the user is on the correct VLAN (via MAC address on switch).

18. What is Clustering?

Clustering connects two or more computers to work together as a single system. This provides High Availability (if one fails, another takes over) and Load Balancing.

19. What is a Group?

A group is a collection of user accounts. Administrators assign permissions to groups rather than individuals to simplify management (e.g., "HR Group" has access to "HR Folder").

20. What is a Child Domain?

A child domain is a sub-domain within an Active Directory forest (e.g., if root is corp.com, child is us.corp.com). It shares the same schema but can have its own administrators.

21. What are the benefits of a Child Domain?

It provides a security boundary, reduces network replication traffic (since it's localized), and allows for decentralized administration.

22. What is an OU (Organizational Unit)?

An OU is a container within Active Directory used to organize users, groups, and computers. It is the smallest unit to which you can link Group Policy Objects (GPO).

23. Explain Group Policy.

Group Policy controls the working environment of user accounts and computer accounts. It can enforce security settings, map drives, install software, and restricts access to Control Panel or specific commands.

24. Difference between Permission, Rights, and Policy?

• Policy: Rules applied to AD containers (Site, Domain, OU).
• Rights: Capabilities assigned to users (e.g., "Log on locally").
• Permissions: Access levels assigned to resources (e.g., "Read/Write" on a file).

25. What do DC and ADC stand for?

DC is Domain Controller. ADC is Additional Domain Controller, which serves as a backup and load balancer for authentication requests.

26. What is the difference between DC and ADC?

Traditionally, the Primary DC held all 5 FSMO roles. The ADC (Additional DC) holds a read-write copy of the directory but may not hold the master roles unless transferred.

27. What are the FSMO Roles?

Forest Roles: Schema Master, Domain Naming Master.
Domain Roles: RID Master, PDC Emulator, Infrastructure Master.

28. What is a "default gateway"?

The default gateway is the router's IP address that forwards traffic destined for outside the local network (like the internet).

29. How do you backup MS Outlook emails?

Use the specific "Import/Export" wizard to export the mailbox to a .PST (Personal Storage Table) file.

30. What is a Trusting vs. Trusted Domain?

In a trust relationship: The Trusting domain has the resources. The Trusted domain has the users who need access.

31. What is Bus Speed?

Bus speed is the rate of communication speed between the CPU (microprocessor) and the RAM/System. It determines how fast data can travel across the motherboard.

32. Name the Active Directory partitions.

• Schema Partition: Defines the objects and attributes that can be created.
• Configuration Partition: Contains network topology information.
• Domain Partition: Holds users, computers, and groups for the specific domain.

33. What is Fixboot?

Fixboot is a recovery command that writes a new partition boot sector onto the system partition. It is used when the boot sector is damaged.

34. How many logical drives can fit onto a physical disk?

On a standard MBR disk, you can have up to 4 primary partitions, or 3 primary and 1 extended partition. The extended partition can hold up to 23 logical drives (limited by drive letters A-Z).

35. What is a B-Router?

A B-Router (Bridge Router) is a device that can function as both a Bridge (forwarding data based on MAC address) and a Router (forwarding data based on IP address).

36. Difference between Gateway and Router?

A Router connects networks using the same protocol. A Gateway connects networks with different architectures or protocols (acting as a translator/converter).

37. What is a Packet?

A packet is a logical grouping of data that contains a header (with source/dest IP) and a payload (user data). It is the fundamental unit of data transfer over a network.

38. What is SCSI?

SCSI (Small Computer System Interface) is a standard for connecting peripheral devices (hard drives, tape drives, scanners) to a computer. It is known for high speed and reliability in server environments.

39. What are the IP Address Classes?

• Class A: 1-126 (Large networks)
• Class B: 128-191 (Medium networks)
• Class C: 192-223 (Small networks, transparently used in homes)
• Class D: 224-239 (Multicast)
• Class E: 240-255 (Experimental/R&D)

40. What is Fixmbr?

Fixmbr is a recovery command that repairs the Master Boot Record (MBR) of the boot disk. It is used when the MBR is corrupted (often by viruses).

41. What is a SID?

SID (Security Identifier) is a unique alphanumeric code assigned to every user, group, and computer object in Windows. Windows uses SIDs, not names, to control access to resources.

42. Difference between Incremental and Differential Backup?

Incremental: Backs up only data changed since the last backup (any type). Faster backup, slower restore.
Differential: Backs up data changed since the last FULL backup. Slower backup, faster restore.

43. Difference between Server OS and Desktop OS?

Server OS is optimized for background services, handling multiple connections, and centralized management (AD, DNS, DHCP). Desktop OS is optimized for user interface, single-user responsiveness, and multimedia.

44. Difference between MSI and EXE?

MSI: A database file used by Windows Installer. It supports standard install/uninstall/repair actions silently. EXE: An executable file that may contain an installer but can also be a standalone program.

45. What is BSOD? How do you troubleshoot it?

(See Question 7). It's a stop error. Fixes: Check RAM, Update Drivers, Scan for Viruses, Check Disk (chkdsk), Review Memory Dump.

46. What is a PTR Record?

A PTR (Pointer) record maps an IP address to a Hostname. It is the opposite of an 'A' record and is used in Reverse Lookup Zones to verify IP identity.

47. What is a Reservation?

In DHCP, a reservation ensures that a specific device (identified by MAC address) always receives the same specific IP address. Useful for printers and servers.

48. What are SMTP and POP?

SMTP: Simple Mail Transfer Protocol (Used for SENDING mail).
POP: Post Office Protocol (Used for RECEIVING/Downloading mail to local storage).

49. What is RIS?

RIS (Remote Installation Services), now WDS (Windows Deployment Services), is used to deploy operating systems over the network to multiple computers simultaneously using PXE boot, saving time.

50. What is a Bootloader?

A bootloader is a small program that loads the main operating system into memory when the computer starts. In Windows, this is the Windows Boot Manager.

51. What is a Blue Screen? How do you fix it?

A Blue Screen (BSOD) indicates a system crash. To fix: Check RAM (reseat it), boot into Safe Mode to remove recent drivers/software, scan for viruses, and check system logs.

52. How to make a Hard Disk dynamic?

Open Disk Management (diskmgmt.msc), right-click the disk, and select "Convert to Dynamic Disk". This requires Administrator privileges.

53. How does Windows protect system files?

Windows File Protection (WFP) prevents critical system files from being replaced. If a file is overwritten, WFP restores the original version from a cached folder (dllcache).

54. Difference between Desktop Support and Help Desk?

Help Desk: First level of support, usually remote (phone/remote tool).
Desktop Support: Second level, involves physical visits to the user's desk for hardware fixes or complex software issues.

55. How to make desktop icons larger/smaller?

Right-click on Desktop > View > Select "Large Icons", "Medium Icons", or "Small Icons". Alternatively, hold CTRL and scroll the mouse wheel.

56. What is TFT?

TFT (Thin Film Transistor) is a type of LCD technology that uses a transistor for each pixel, improving image quality and response time on flat-panel displays.

57. What is LCD?

LCD (Liquid Crystal Display) is a display technology that uses liquid crystals to block or allow light to pass through. It is energy-efficient and lightweight.

58. How do you troubleshoot Outlook?

1. Check internet connectivity.
2. Verify server settings (Exchange/POP/IMAP).
3. Repair the Outlook Profile or create a new one.
4. Run Outlook in Safe Mode (outlook.exe /safe) to disable add-ins.
5. Recreate the OST/PST file.

59. How to resize desktop icons?

(See Question 55). Right-click Desktop > View > Select size.

60. Best way to access a remote client?

Use MSTSC (Remote Desktop Connection) for Windows-to-Windows within a network. For external support, use tools like TeamViewer, AnyDesk, or LogMeIn.

61. How to install OS on 50 PCs simultaneously?

Use network deployment tools like WDS (Windows Deployment Services) or SCCM. Alternatively, creates a "Ghost" image of one PC and multicast it to others using Symantec Ghost or Clonezilla.

62. How to install a network printer?

Go to Devices and Printers > Add a Printer > "Add a network, wireless or Bluetooth printer". Select the printer from the list or enter its IP address. Install drivers if prompted.

63. How to enable auto-login?

Run netplwiz (or control userpasswords2). Uncheck "Users must enter a user name and password to use this computer", apply, and enter the credentials to be used for auto-login.

64. What is the Print Spooler?

The Print Spooler is a service that manages print jobs. It stores print jobs in memory or on disk until the printer is ready. If printing gets stuck, restarting this service usually fixes it.

65. What is a Firewire port?

Firewire (IEEE 1394) is a high-speed interface for connecting peripherals like digital camcorders and external hard drives. It supports faster data transfer rates (up to 800 Mbps) than older USB standards.