Electronic data processing personnel Certification 1.307 Examinations 1.160 Computer networks 470 Study guides 415 Microsoft software 354 Computer technicians 126 Operating systems (Computers) 100 Microsoft Windows (Computer file) 98 Security measures 75 Computer security 72 Microsoft Windows server 67 Maintenance and repair 66 Microcomputers 66 Internetworking (Telecommunication) 65 Java (Computer program language) 53 Database management 47 Microsoft .NET Framework 42 Routers (Computer networks) 41 Oracle (Computer file) 35 Development 33 Telecommunication 30 Application software 29 Client/server computing 27 Telecommunications engineers 27 Switching systems 25 TCP/IP (Computer network protocol) 25 Directory services (Computer network technology) 24 Management 21 Design 19