Glen E. Clarke, MCSE, MCDBA, MCSD, CompTIA A+, CompTIA Network+, CompTIA Security+, is an independent trainer and consultant, focusing on network security and security auditing services. He delivers certified courses on Windows Server, SQL Server, Exchange Server, Visual Basic .NET, and ASP.NET. Clarke is a co-author of "CompTIA Security+ Certification Practice Exams, Mike Meyers CompTIA Network+ Certification Passport, Third Edition" (both McGraw-Hill), "A+ Bible", and "A+ For Dummies" (both Wiley). He is the author of previous editions of this book and "CompTIA Security+ Certification Study