Editing Windows Notepad (section)

== Limitations ==
Notepad used a built-in [[window class]] named ''EDIT''. The maximum file size Notepad can open depends on operating system limitations on the size of the ''EDIT'' window class, with a different limit in each version of Windows. Because of this limitation, on [[Windows 3.0]], [[Windows 3.1]], and [[Windows 3.11]], Notepad could not open files larger than 54&nbsp;[[Kilobyte|KB]]. (Microsoft recommended using another text editor for opening files larger than 45&nbsp;KB.)<ref>{{cite web |date=September 24, 2011 |title=Maximum File Size Limits for Notepad |url=https://support.microsoft.com/en-us/kb/59578 |access-date=2016-10-28 |website=Support |publisher=[[Microsoft]] |url-status=dead |archive-url=https://web.archive.org/web/20150317213210/http://support.microsoft.com/en-us/kb/59578 |archive-date=2015-03-17}}</ref> This limit was extended to 64&nbsp;KB in [[Windows 95]], with users now directed to [[WordPad]] for larger files. On [[Windows XP]], Notepad was limited to 32&nbsp;[[Megabyte|MB]] and declined to open bigger files.<ref>{{cite web |date=October 24, 2007 |title=What is file size limit for Notepad in Windows XP |url=https://bytes.com/topic/desktop-software/answers/727862-what-file-size-limit-notepad-windows-xp |website=Bytes |access-date=2016-10-28 |url-status=live |archive-url=https://web.archive.org/web/20161029045531/https://bytes.com/topic/desktop-software/answers/727862-what-file-size-limit-notepad-windows-xp |archive-date=2016-10-29}}</ref> On [[Windows 11]], Notepad uses the [[Text Object Model|RichEdit]] control.<ref>{{Cite web |date=2022-02-23 |title=Windows 11 Notepad |url=https://devblogs.microsoft.com/math-in-office/windows-11-notepad/ |access-date=2022-03-30 |website=Math in Office |language=en-US}}</ref> The size limit was raised to about 1&nbsp;[[Gigabyte|GB]], and attempting to open any file larger than that shows a [[dialog box]] suggesting that the user open it with a different text editor.<ref>{{cite book|url=https://books.google.com/books?id=gLZeEAAAQBAJ&pg=PT557|title=Windows 11 All-in-One For Dummies|last=Rusen|first=Ciprian Adrian|publisher=[[Wiley (publisher)|Wiley]]|date=2022|access-date=2022-03-08|page=557|isbn=978-1-119-85870-6}}</ref>

===Unicode detection===
{{Main article|Bush hid the facts}}
On the [[Windows NT family]] of operating systems (including [[Windows 2000]] and [[Windows XP]]), Notepad can detect Unicode files even when they lack a [[byte order mark]]. To do this, it calls the <code>IsTextUnicode()</code> function of the [[Windows API]].<ref>{{cite web |url=https://msdn.microsoft.com/en-us/library/dd318672(v=vs.85).aspx |title=IsTextUnicode() |work=[[MSDN]] |publisher=[[Microsoft]] |access-date=January 28, 2017 |url-status=live |archive-url=https://web.archive.org/web/20160910175750/https://msdn.microsoft.com/en-us/library/dd318672(v=vs.85).aspx |archive-date=2016-09-10}}</ref> Until [[Windows Vista]], this function was imperfect, incorrectly identifying some all-lowercase [[ASCII]] text as UTF-16. As a result, Notepad interpreted a file containing a phrase like "aaaa aaa aaa aaaaa" ("4-3-3-5") as a two-byte-encoded Unicode text file. If a font with support for Chinese was installed, nine Chinese characters (桴獩愠灰挠湡戠敲歡) would display. Otherwise, it would display square [[substitute character]]s instead of Chinese characters. This issue was resolved on Windows Vista and newer.<ref>{{cite web|last=Chen|first=Raymond|date=April 17, 2007|title=The Notepad file encoding problem, redux|url=https://devblogs.microsoft.com/oldnewthing/20070417-00/?p=27223|url-status=live|archive-url=https://web.archive.org/web/20110903031351/http://blogs.msdn.com/b/oldnewthing/archive/2007/04/17/2158334.aspx|archive-date=2011-09-03|access-date=2019-03-20|work=The Old New Thing|publisher=[[Microsoft]]}}</ref><ref>{{cite web|last=Kaplan|first=Michael S.|date=March 25, 2008|title=Bush might've still hid the facts, but he can't hide them from Vista SP1/Server 2008 Notepad|url=http://archives.miloush.net/michkap/archive/2008/03/25/8334796.html|access-date=13 April 2017}}</ref>