Microsoft Certified Desktop Support Technician (MCDST) is an entry-level certification that can enhance a candidate’s IT professional career. It covers the skills of a help desk technician, customer support representative, PC support specialist, technical support representative, and technical support specialist, as defined by the National Workforce Center for Emerging Technologies Skill Standards for Information Technology and other research worldwide.
The MCDST credential proves that you have the skills to successfully support end users and to successfully troubleshoot desktop environments running on the Microsoft Windows operating system.
Candidates for this credential typically work in small- to medium-sized computing environments supporting end-users that use Microsoft Windows XP Professional or Microsoft Windows 2000 Professional as a desktop operating system.
IT managers find the MCDST to be a valuable resource, as they face a constant challenge recruiting and training professionals, and who also need to ensure consistent, high-quality help-desk support for knowledge workers using the Microsoft Windows desktop.
MCDST candidates are required to pass two core exams. Elective exams are not required.
For more information:
http://www.microsoft.com/learning/mcp/mcdst/requirements.asp
CORE EXAMS
(70-271) Support Windows XP OS 

(70-272) Troubleshoot Desktop Applications 
