{"id":7573,"date":"2012-05-21T07:00:00","date_gmt":"2012-05-21T07:00:00","guid":{"rendered":"https:\/\/blogs.msdn.microsoft.com\/oldnewthing\/2012\/05\/21\/what-was-the-registry-like-in-16-bit-windows\/"},"modified":"2012-05-21T07:00:00","modified_gmt":"2012-05-21T07:00:00","slug":"what-was-the-registry-like-in-16-bit-windows","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20120521-00\/?p=7573\/","title":{"rendered":"What was the registry like in 16-bit Windows?"},"content":{"rendered":"<p>Commenter Niels wonders <a href=\"http:\/\/blogs.msdn.com\/b\/oldnewthing\/archive\/2008\/01\/17\/7137438.aspx\"> when and how the registry was introduced to 16-bit Windows<\/a> and how much of it carried over to Windows&nbsp;95.\n The 16-bit registry was <a href=\"http:\/\/blogs.msdn.com\/b\/oldnewthing\/archive\/2008\/01\/17\/7137438.aspx\"> extremely simple<\/a>. There were just keys, no values. The only <a href=\"http:\/\/blogs.msdn.com\/b\/oldnewthing\/archive\/2003\/08\/08\/54618.aspx\"> hive<\/a> was <code>HKEY_CLASSES_ROOT<\/code>. All it was used for was COM objects and file associations. The registry was stored in the <code>REG.DAT<\/code> file, and its maximum size was 64<a href=\"http:\/\/blogs.msdn.com\/b\/oldnewthing\/archive\/2009\/06\/11\/9725386.aspx\">KB<\/a>.\n It is my recollection that the registry was introduced in Windows&nbsp;3.1, but Niels says it&#8217;s not in a plain vanilla install, so I guess my memory is faulty.\n None of the 16-bit registry code was carried over to Windows&nbsp;95. Windows&nbsp;95 extended the registry into kernel mode, added support for values and non-string data types, increased the maximum registry size (though if some people are to be believed, not by enough), and added a bunch of other hives, like added the <code>HKEY_CURRENT_USER<\/code>, <code>HKEY_LOCAL_MACHINE<\/code>, and the <code>HKEY_DYN_DATA<\/code>, The old 16-bit registry code was woefully inadequate for all these new requirements (especially the kernel mode part), so it was all thrown out and a brand new registry written.<\/p>\n<p> In the early days of the Windows&nbsp;95 registry, the in-memory <a href=\"http:\/\/blogs.msdn.com\/b\/oldnewthing\/archive\/2007\/06\/04\/3069949.aspx\"> signature value<\/a> to identify the data structures which represent an open registry key were four bytes which corresponded to the ASCII values for the initials of the two programmers who wrote it. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Commenter Niels wonders when and how the registry was introduced to 16-bit Windows and how much of it carried over to Windows&nbsp;95. The 16-bit registry was extremely simple. There were just keys, no values. The only hive was HKEY_CLASSES_ROOT. All it was used for was COM objects and file associations. The registry was stored in [&hellip;]<\/p>\n","protected":false},"author":1069,"featured_media":111744,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[2],"class_list":["post-7573","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-history"],"acf":[],"blog_post_summary":"<p>Commenter Niels wonders when and how the registry was introduced to 16-bit Windows and how much of it carried over to Windows&nbsp;95. The 16-bit registry was extremely simple. There were just keys, no values. The only hive was HKEY_CLASSES_ROOT. All it was used for was COM objects and file associations. The registry was stored in [&hellip;]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/7573","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/users\/1069"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/comments?post=7573"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/7573\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media\/111744"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/media?parent=7573"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=7573"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=7573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}