Level 2. Same as Level 1, with the following additional education and experience: Bachelor's degree in Computer Science, Information Technology, or related discipline; or a minimum of 5 years' experience installing, maintaining, administering, and supporting computer hardware and operating systems software such as Windows, HP-UNIX, LINUX, VMware, ESX, or Active Directory. Level 4. Same as Level 3 with the following additional education and experience: Bachelor's degree in Computer Science, Information Technology, or related discipline; or a minimum of 10 years' experience installing, maintaining, administrating and supporting computer hardware and operating systems software such as Windows, HP-UNIX, LINUX, VMware, ESX, or Active Directory.