List of Probable questions - Desktop support

When you apply for a Desktop level job, besides asking general questions about yourself the interviewer will also ask you questions that test your technical proficiency.
Desktop Support Engineers are required to have deep understanding of basic as well as intermediate level concepts. The interviewer can ask you to explain the concept of OSI model or TCP/IP model or can also ask you fact based questions to test your memory power. They can ask you questions on Desktop or Server level questions.

1. What are the types of Operating System ?
2. Give examples of NOS (Network Operating System) and SOS (Server Operating System)
3. Difference between FAT and NTFS
4. Enhancements in Windows 2003 from Windows 2000
5. Enhancements in Windows 2003 from Windows NT
6. What is Active Directory ?
7. Types of Firewall
8. Difference between Hardware and Software Firewall
9. Name the seven layers of OSI model
10. How to enable Firewall in Windows XP?
11. How to Disable Firewall in Windows XP?
12. Minimum System requirement of Windows XP, Vista, 2003 and 2008
13. Explain ping command
14. Explain Cookies
15. How to boot the computer in Safe mode
16. Types of printer
17. Explain Last Known Good Configuration
18. What is Disk clean up, Disk Defragmentation, Device manager and System Restore
19. USB port Vs Firewire port
20. How to install a printer in Windows XP?
21. What is a Browser and name any 5 browsers ?
22. Serial port Vs Parallel port
23. What is a port number ?
24. Where is the HOSTS file located
25. Explain different RAID levels
26. Explain APIPA, IP address and Subnet mask
27. Difference between IP v4 and IP v6
28. How to remove virus from a computer
29. How to make a computer run faster?
30. What is attrib command ?
31. What is edit command ?
32. How to copy a file or folder using copy command?
33. How to format the hard disk using command line utilities?
34. Explain mkdir, rmdir and chdir commands
35. Types of hard disk
36. Difference between primary and secondary partition
37. Types of backups in Window OS
38. Differential Backup Vs Incremental Backup Vs Copy backup
39. What is remote desktop.
40. Recovery Console Vs Automated System Recovery
41. What is NTLDR file?
42. How to tackle "missing NTLDR file" error?
43. How many bytes are there in MAC address
44. Range of Class A IP address
45. Range of Class B IP address
46. Range of Class C IP address
47. Default subnet mask of Class A, Class B and Class C IP address
48. What is BSOD (Blue Screen of Death) and how to overcome it
49. Difference between Preferred DNS and Alternate DNS server
50. Transmission speed of T1 carrier

I could go on and on forever writing questions and you could also go on and on searching for "Desktop Support Engineer Interview Question", but the fact is that if you are going for L1 (level 1) positions you only need to do your basics well.

(lol..).