I have experience using the following versions of MS-DOS (4.1, 5.0, 6.0, 6.2, 6.22) and the Linux version of DOSemu. I can partition and reformat drives, install all the above listed versions of DOS and know all file and directory manipulation commands. Like all command line based systems, pathing and syntax make the difference between restoring or destroying data. I am also familiar with configuring memory for running programs on DOS based systems and even networking with them. Yes, there is a DOS based TCP/IP stack. I am also proficient in writing DOS based scripts(batch files).
I have been a linux user since 1999. I have worked with Red Hat, Ubuntu and Debian linux distributions. My first experience was with an Internet service provider where I administrated primary and secondary Mail (pop, smtp), DNS (bind), Authentication (Radius), and web (HTTP) servers. Currently, I am working as a Systems Administrator, primarily working on Samba and Active Directory integration along with ACL (Access Control List) for securing company confidential data. FTP and HTTP servers are also primary systems I administrate. I am also familiar with RAID and iSCSI technology as well as server virtualization.
The company I work for uses MS Outlook versions 2003/2007/2010. I support and configure all user settings for Outlook and support all problems with Calendars, Contacts, Tasks and especially .PST files. I am familiar with setting up Outlook for POP/IMAP and Exchange and for either SSL and non-encrypted settings. I am also capable of copying all user settings (contacts, email dropdown list, calendar items, and tasks) from one machine to another and even between different versions of Outlook. I can successfully restore/repair damaged mail folder with the scanpst.exe tool.
With 15 years of experience supporting Windows Desktops and Laptops and now netbooks, I have had to be proficient with versions starting with Windows 3.11, Windows 95(a and b), Windows 98 (1st, and 2nd editions), Windows CE, Windows ME, Windows NT (3.5 and 4.0), Windows 2000, Windows XP, Vista and Windows 7. In all cases, I have loaded the operating system, supported the operating system, configured the networks, printers and file sharing. Also, I have worked with Server platforms such as older Windows NT server and newer Windows 2003/2008 Server with Active Directory support. Also, with later version, I am familiar with both the 32-bit and 64-bit versions.
My first experience with networking was with Lantastic, a 10-base-T coaxial network back in 1994, later I became acquainted with Token-Ring networks, which are also coaxial based. Since then, I have kept up with the progression from 10 MB Ethernet CATV networks, through 100MG and now 1GB. During my years working at an ISP, I also had to manage routers, managed (intelligent) switches and DSL over copper phone line equipment. Eventually, we branched into wireless networking as well, starting with the original 8011.b 11MB standard based on 2.4Ghz line of sight technology. Troubleshooting and managing LAN and WAN networks has been part of my job description since 1994.
Working as a systems administrator, there many times that there is a lot of text data in logs and other formats to process. This is where learning PERL (Practical Extraction and Report Language) becomes necessary. I developed a complicated PERL script to monitor modem pools for users online usage and activity while working at an ISP. It kept track of their time logged in, number of total logins per month, locations logged in from, and prevented multiple logins.
PERL is not a programming language, rather it is a scripting language. However, it is still a core competent in all Linux/UNIX systems because it is used from everything from web development, to database maintenance, user and system administration and of course for extracting information from text files.