Microsoft Windows Server comes in various versions (e.g., 2008, 2008 R2, 2012, and 2012 R2) and editions (e.g., Foundation, Essentials, Standard, and Datacenter). With all of these names, it may be difficult to understand the differences and know which flavor you should use. First, don't confuse the version with the edition. The version specifies various releases of the software, whereas the editions specify different variants that mainly concern degrees of privilege in the licensing. Since the year 2000, Windows Server versions have been named by a year and sometimes the designation "R2" for "release 2," which refers to a later version. For example, in 2013, instead of releasing version "2013," Microsoft called the new version "Windows Server 2012 R2."
If you frequently install new software programs, and then remove them when you’ve finished so as not to clutter up your system, you may be surprised to see them still appear in your Add/Remove Programs list. Sometimes a program’s uninstall operation doesn’t completely remove all traces of the program from your system. Luckily, with a simple registry edit, you can remove these programs from the list.