{"id":112213,"date":"2026-04-07T07:00:00","date_gmt":"2026-04-07T14:00:00","guid":{"rendered":"https:\/\/devblogs.microsoft.com\/oldnewthing\/?p=112213"},"modified":"2026-04-07T12:51:28","modified_gmt":"2026-04-07T19:51:28","slug":"20260407-00","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/oldnewthing\/20260407-00\/?p=112213","title":{"rendered":"Were there any Windows 3.1 programs that were so incompatible with Windows 95 that there was no point trying to patch them?"},"content":{"rendered":"

In a comment to my discussion of the Windows 95 patch system, commenter word merchant wondered whether there were any Windows 3.1 programs or drivers that were so incompatible with Windows 95 that there was no point trying to patch them<\/a>.<\/p>\n

Yes, there were problems that were so bad that the program was effectively unfixable. The largest category of them were those which took various types of handles and figured out how to convert them to pointers, and then used those pointers to access (and sometimes modify!) the internal implementation details of those objects.\u00b9 Not only did the implementation details change, but the mechanism they used to convert handles to pointers also stopped working because Windows 95 used a 32-bit heap for user interface and graphics objects, whereas Windows 3.1 used a 16-bit heap.<\/p>\n

Sometimes the programs were kind enough to do strict version checks to confirm that they were running on a system whose internals they understood. Sometimes their version checks were themselves broken, like one program that assumed that if the Windows version is not 3.0, 3.1, or 2.1, then it must be 2.0!<\/p>\n

There were other one-off problems, like programs which detoured APIs in a way that no longer worked, but the ones that dug into operating system internals were by far the most common.<\/p>\n

\u00b9 What’s particularly frustrating is the cases where the program did this to access internal implementation details, when the information they wanted was already exposed by a public and supported API.<\/p>\n","protected":false},"excerpt":{"rendered":"

The permanently ineligible list.<\/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-112213","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-oldnewthing","tag-history"],"acf":[],"blog_post_summary":"

The permanently ineligible list.<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/112213","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=112213"}],"version-history":[{"count":1,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/112213\/revisions"}],"predecessor-version":[{"id":112214,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/posts\/112213\/revisions\/112214"}],"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=112213"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/categories?post=112213"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/oldnewthing\/wp-json\/wp\/v2\/tags?post=112213"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}