Electronic data processing personnel 1 311 Certification 1 309 Examinations 1 155 Computer networks 461 Study guides 415 Microsoft software 353 Computer technicians 126 Operating systems (Computers) 102 Microsoft Windows (Computer file) 93 Security measures 73 Computer security 72 Microsoft Windows server 67 Maintenance and repair 66 Microcomputers 66 Internetworking (Telecommunication) 64 Java (Computer program language) 53 Database management 47 Microsoft .NET Framework 42 Routers (Computer networks) 41 Development 33 Oracle (Computer file) 33 Application software 29 Telecommunication 29 Client/server computing 27 Telecommunications engineers 27 TCP/IP (Computer network protocol) 25 Directory services (Computer network technology) 24 Switching systems 24 Design 19 Computer network protocols 18