new file mode 100644
--- /dev/null
+++ b/src/dosinst.h
@@ -0,0 +1,645 @@
+/* vi:set ts=8 sts=4 sw=4:
+ *
+ * VIM - Vi IMproved	by Bram Moolenaar
+ *
+ * Do ":help uganda"  in Vim to read copying and usage conditions.
+ * Do ":help credits" in Vim to see a list of people who contributed.
+ * See README.txt for an overview of the Vim source code.
+ */
+/*
+ * dosinst.h: Common code for dosinst.c and uninstal.c
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#ifndef UNIX_LINT
+# include <io.h>
+# include <ctype.h>
+
+# ifndef __CYGWIN__
+#  include <direct.h>
+# endif
+
+# if defined(_WIN64) || defined(WIN32)
+#  define WIN3264
+#  include <windows.h>
+#  include <shlobj.h>
+# else
+#  include <dir.h>
+#  include <bios.h>
+#  include <dos.h>
+# endif
+#endif
+
+#ifdef UNIX_LINT
+/* Running lint on Unix: Some things are missing. */
+char *searchpath(char *name);
+#endif
+
+#if defined(DJGPP) || defined(UNIX_LINT)
+# include <unistd.h>
+# include <errno.h>
+#endif
+
+#include "version.h"
+
+#if defined(DJGPP) || defined(UNIX_LINT)
+# define vim_mkdir(x, y) mkdir((char *)(x), y)
+#else
+# if defined(WIN3264) && !defined(__BORLANDC__)
+#  define vim_mkdir(x, y) _mkdir((char *)(x))
+# else
+#  define vim_mkdir(x, y) mkdir((char *)(x))
+# endif
+#endif
+/* ---------------------------------------- */
+
+
+#define BUFSIZE 512		/* long enough to hold a file name path */
+#define NUL 0
+
+#define FAIL 0
+#define OK 1
+
+#ifndef FALSE
+# define FALSE 0
+#endif
+#ifndef TRUE
+# define TRUE 1
+#endif
+
+#define VIM_STARTMENU "Programs\\Vim " VIM_VERSION_SHORT
+
+int	interactive;		/* non-zero when running interactively */
+
+/*
+ * Call malloc() and exit when out of memory.
+ */
+    static void *
+alloc(int len)
+{
+    char *s;
+
+    s = malloc(len);
+    if (s == NULL)
+    {
+	printf("ERROR: out of memory\n");
+	exit(1);
+    }
+    return (void *)s;
+}
+
+/*
+ * The toupper() in Bcc 5.5 doesn't work, use our own implementation.
+ */
+    static int
+mytoupper(int c)
+{
+    if (c >= 'a' && c <= 'z')
+	return c - 'a' + 'A';
+    return c;
+}
+
+    static void
+myexit(int n)
+{
+    if (!interactive)
+    {
+	/* Present a prompt, otherwise error messages can't be read. */
+	printf("Press Enter to continue\n");
+	rewind(stdin);
+	(void)getchar();
+    }
+    exit(n);
+}
+
+#ifdef WIN3264
+/* This symbol is not defined in older versions of the SDK or Visual C++ */
+
+#ifndef VER_PLATFORM_WIN32_WINDOWS
+# define VER_PLATFORM_WIN32_WINDOWS 1
+#endif
+
+static DWORD g_PlatformId;
+
+/*
+ * Set g_PlatformId to VER_PLATFORM_WIN32_NT (NT) or
+ * VER_PLATFORM_WIN32_WINDOWS (Win95).
+ */
+    static void
+PlatformId(void)
+{
+    static int done = FALSE;
+
+    if (!done)
+    {
+	OSVERSIONINFO ovi;
+
+	ovi.dwOSVersionInfoSize = sizeof(ovi);
+	GetVersionEx(&ovi);
+
+	g_PlatformId = ovi.dwPlatformId;
+	done = TRUE;
+    }
+}
+
+# ifdef __BORLANDC__
+/* Borland defines its own searchpath() in dir.h */
+#  include <dir.h>
+# else
+    static char *
+searchpath(char *name)
+{
+    static char widename[2 * BUFSIZE];
+    static char location[2 * BUFSIZE + 2];
+
+    /* There appears to be a bug in FindExecutableA() on Windows NT.
+     * Use FindExecutableW() instead... */
+    PlatformId();
+    if (g_PlatformId == VER_PLATFORM_WIN32_NT)
+    {
+	MultiByteToWideChar(CP_ACP, 0, (LPCTSTR)name, -1,
+		(LPWSTR)widename, BUFSIZE);
+	if (FindExecutableW((LPCWSTR)widename, (LPCWSTR)"",
+		    (LPWSTR)location) > (HINSTANCE)32)
+	{
+	    WideCharToMultiByte(CP_ACP, 0, (LPWSTR)location, -1,
+		    (LPSTR)widename, 2 * BUFSIZE, NULL, NULL);
+	    return widename;
+	}
+    }
+    else
+    {
+	if (FindExecutableA((LPCTSTR)name, (LPCTSTR)"",
+		    (LPTSTR)location) > (HINSTANCE)32)
+	    return location;
+    }
+    return NULL;
+}
+# endif
+#endif
+
+/*
+ * Call searchpath() and save the result in allocated memory, or return NULL.
+ */
+    static char *
+searchpath_save(char *name)
+{
+    char	*p;
+    char	*s;
+
+    p = searchpath(name);
+    if (p == NULL)
+	return NULL;
+    s = alloc(strlen(p) + 1);
+    strcpy(s, p);
+    return s;
+}
+
+#ifdef WIN3264
+/*
+ * Get the path to a requested Windows shell folder.
+ *
+ * Return FAIL on error, OK on success
+ */
+    int
+get_shell_folder_path(
+	char *shell_folder_path,
+	const char *shell_folder_name)
+{
+    /*
+     * The following code was successfully built with make_mvc.mak.
+     * The resulting executable worked on Windows 95, Millennium Edition, and
+     * 2000 Professional.  But it was changed after testing...
+     */
+    LPITEMIDLIST    pidl = 0; /* Pointer to an Item ID list allocated below */
+    LPMALLOC	    pMalloc;  /* Pointer to an IMalloc interface */
+    int		    csidl;
+    int		    alt_csidl = -1;
+    static int	    desktop_csidl = -1;
+    static int	    programs_csidl = -1;
+    int		    *pcsidl;
+    int		    r;
+
+    if (strcmp(shell_folder_name, "desktop") == 0)
+    {
+	pcsidl = &desktop_csidl;
+#ifdef CSIDL_COMMON_DESKTOPDIRECTORY
+	csidl = CSIDL_COMMON_DESKTOPDIRECTORY;
+	alt_csidl = CSIDL_DESKTOP;
+#else
+	csidl = CSIDL_DESKTOP;
+#endif
+    }
+    else if (strncmp(shell_folder_name, "Programs", 8) == 0)
+    {
+	pcsidl = &programs_csidl;
+#ifdef CSIDL_COMMON_PROGRAMS
+	csidl = CSIDL_COMMON_PROGRAMS;
+	alt_csidl = CSIDL_PROGRAMS;
+#else
+	csidl = CSIDL_PROGRAMS;
+#endif
+    }
+    else
+    {
+	printf("\nERROR (internal) unrecognised shell_folder_name: \"%s\"\n\n",
+							   shell_folder_name);
+	return FAIL;
+    }
+
+    /* Did this stuff before, use the same ID again. */
+    if (*pcsidl >= 0)
+    {
+	csidl = *pcsidl;
+	alt_csidl = -1;
+    }
+
+retry:
+    /* Initialize pointer to IMalloc interface */
+    if (NOERROR != SHGetMalloc(&pMalloc))
+    {
+	printf("\nERROR getting interface for shell_folder_name: \"%s\"\n\n",
+							   shell_folder_name);
+	return FAIL;
+    }
+
+    /* Get an ITEMIDLIST corresponding to the folder code */
+    if (NOERROR != SHGetSpecialFolderLocation(0, csidl, &pidl))
+    {
+	if (alt_csidl < 0 || NOERROR != SHGetSpecialFolderLocation(0,
+							    alt_csidl, &pidl))
+	{
+	    printf("\nERROR getting ITEMIDLIST for shell_folder_name: \"%s\"\n\n",
+							   shell_folder_name);
+	    return FAIL;
+	}
+	csidl = alt_csidl;
+	alt_csidl = -1;
+    }
+
+    /* Translate that ITEMIDLIST to a string */
+    r = SHGetPathFromIDList(pidl, shell_folder_path);
+
+    /* Free the data associated with pidl */
+    pMalloc->lpVtbl->Free(pMalloc, pidl);
+    /* Release the IMalloc interface */
+    pMalloc->lpVtbl->Release(pMalloc);
+
+    if (!r)
+    {
+	if (alt_csidl >= 0)
+	{
+	    /* We probably get here for Windows 95: the "all users"
+	     * desktop/start menu entry doesn't exist. */
+	    csidl = alt_csidl;
+	    alt_csidl = -1;
+	    goto retry;
+	}
+	printf("\nERROR translating ITEMIDLIST for shell_folder_name: \"%s\"\n\n",
+							   shell_folder_name);
+	return FAIL;
+    }
+
+    /* If there is an alternative: verify we can write in this directory.
+     * This should cause a retry when the "all users" directory exists but we
+     * are a normal user and can't write there. */
+    if (alt_csidl >= 0)
+    {
+	char tbuf[BUFSIZE];
+	FILE *fd;
+
+	strcpy(tbuf, shell_folder_path);
+	strcat(tbuf, "\\vim write test");
+	fd = fopen(tbuf, "w");
+	if (fd == NULL)
+	{
+	    csidl = alt_csidl;
+	    alt_csidl = -1;
+	    goto retry;
+	}
+	fclose(fd);
+	unlink(tbuf);
+    }
+
+    /*
+     * Keep the found csidl for next time, so that we don't have to do the
+     * write test every time.
+     */
+    if (*pcsidl < 0)
+	*pcsidl = csidl;
+
+    if (strncmp(shell_folder_name, "Programs\\", 9) == 0)
+	strcat(shell_folder_path, shell_folder_name + 8);
+
+    return OK;
+}
+#endif
+
+/*
+ * List of targets.  The first one (index zero) is used for the default path
+ * for the batch files.
+ */
+#define TARGET_COUNT  8
+
+struct
+{
+    char	*name;		/* Vim exe name (without .exe) */
+    char	*batname;	/* batch file name */
+    char	*lnkname;	/* shortcut file name */
+    char	*exename;	/* exe file name */
+    char	*exenamearg;	/* exe file name when using exearg */
+    char	*exearg;	/* argument for vim.exe or gvim.exe */
+    char	*oldbat;	/* path to existing xxx.bat or NULL */
+    char	*oldexe;	/* path to existing xxx.exe or NULL */
+    char	batpath[BUFSIZE];  /* path of batch file to create; not
+				      created when it's empty */
+} targets[TARGET_COUNT] =
+{
+    {"all",	"batch files"},
+    {"vim",	"vim.bat",	"Vim.lnk",
+					"vim.exe",    "vim.exe",  ""},
+    {"gvim",	"gvim.bat",	"gVim.lnk",
+					"gvim.exe",   "gvim.exe", ""},
+    {"evim",	"evim.bat",	"gVim Easy.lnk",
+					"evim.exe",   "gvim.exe", "-y"},
+    {"view",	"view.bat",	"Vim Read-only.lnk",
+					"view.exe",   "vim.exe",  "-R"},
+    {"gview",	"gview.bat",	"gVim Read-only.lnk",
+					"gview.exe",  "gvim.exe", "-R"},
+    {"vimdiff", "vimdiff.bat",	"Vim Diff.lnk",
+					"vimdiff.exe","vim.exe",  "-d"},
+    {"gvimdiff","gvimdiff.bat",	"gVim Diff.lnk",
+					"gvimdiff.exe","gvim.exe", "-d"},
+};
+
+#define ICON_COUNT 3
+char *(icon_names[ICON_COUNT]) =
+	{"gVim " VIM_VERSION_SHORT,
+	 "gVim Easy " VIM_VERSION_SHORT,
+	 "gVim Read only " VIM_VERSION_SHORT};
+char *(icon_link_names[ICON_COUNT]) =
+	{"gVim " VIM_VERSION_SHORT ".lnk",
+	 "gVim Easy " VIM_VERSION_SHORT ".lnk",
+	 "gVim Read only " VIM_VERSION_SHORT ".lnk"};
+
+/* This is only used for dosinst.c and for uninstal.c when not being able to
+ * directly access registry entries. */
+#if !defined(WIN3264) || defined(DOSINST)
+/*
+ * Run an external command and wait for it to finish.
+ */
+    static void
+run_command(char *cmd)
+{
+    char	*cmd_path;
+    char	cmd_buf[BUFSIZE];
+    char	*p;
+
+    /* On WinNT, 'start' is a shell built-in for cmd.exe rather than an
+     * executable (start.exe) like in Win9x.  DJGPP, being a DOS program,
+     * is given the COMSPEC command.com by WinNT, so we have to find
+     * cmd.exe manually and use it. */
+    cmd_path = searchpath_save("cmd.exe");
+    if (cmd_path != NULL)
+    {
+	/* There is a cmd.exe, so this might be Windows NT.  If it is,
+	 * we need to call cmd.exe explicitly.  If it is a later OS,
+	 * calling cmd.exe won't hurt if it is present.
+	 * Also, "wait" on NT expects a window title argument.
+	 */
+	/* Replace the slashes with backslashes. */
+	while ((p = strchr(cmd_path, '/')) != NULL)
+	    *p = '\\';
+	sprintf(cmd_buf, "%s /c start \"vimcmd\" /w %s", cmd_path, cmd);
+	free(cmd_path);
+    }
+    else
+    {
+	/* No cmd.exe, just make the call and let the system handle it. */
+	sprintf(cmd_buf, "start /w %s", cmd);
+    }
+    system(cmd_buf);
+}
+#endif
+
+/*
+ * Append a backslash to "name" if there isn't one yet.
+ */
+    static void
+add_pathsep(char *name)
+{
+    int		len = strlen(name);
+
+    if (len > 0 && name[len - 1] != '\\' && name[len - 1] != '/')
+	strcat(name, "\\");
+}
+
+/*
+ * The normal chdir() does not change the default drive.  This one does.
+ */
+/*ARGSUSED*/
+    int
+change_drive(int drive)
+{
+#ifdef WIN3264
+    char temp[3] = "-:";
+    temp[0] = (char)(drive + 'A' - 1);
+    return !SetCurrentDirectory(temp);
+#else
+# ifndef UNIX_LINT
+    union REGS regs;
+
+    regs.h.ah = 0x0e;
+    regs.h.dl = drive - 1;
+    intdos(&regs, &regs);   /* set default drive */
+    regs.h.ah = 0x19;
+    intdos(&regs, &regs);   /* get default drive */
+    if (regs.h.al == drive - 1)
+	return 0;
+# endif
+    return -1;
+#endif
+}
+
+/*
+ * Change directory to "path".
+ * Return 0 for success, -1 for failure.
+ */
+    int
+mch_chdir(char *path)
+{
+    if (path[0] == NUL)		/* just checking... */
+	return 0;
+    if (path[1] == ':')		/* has a drive name */
+    {
+	if (change_drive(mytoupper(path[0]) - 'A' + 1))
+	    return -1;		/* invalid drive name */
+	path += 2;
+    }
+    if (*path == NUL)		/* drive name only */
+	return 0;
+    return chdir(path);		/* let the normal chdir() do the rest */
+}
+
+/*
+ * Expand the executable name into a full path name.
+ */
+#if defined(__BORLANDC__) && !defined(WIN3264)
+
+/* Only Borland C++ has this. */
+# define my_fullpath(b, n, l) _fullpath(b, n, l)
+
+#else
+    static char *
+my_fullpath(char *buf, char *fname, int len)
+{
+# ifdef WIN3264
+    /* Only GetModuleFileName() will get the long file name path.
+     * GetFullPathName() may still use the short (FAT) name. */
+    DWORD len_read = GetModuleFileName(NULL, buf, (size_t)len);
+
+    return (len_read > 0 && len_read < (DWORD)len) ? buf : NULL;
+# else
+    char	olddir[BUFSIZE];
+    char	*p, *q;
+    int		c;
+    char	*retval = buf;
+
+    if (strchr(fname, ':') != NULL)	/* allready expanded */
+    {
+	strncpy(buf, fname, len);
+    }
+    else
+    {
+	*buf = NUL;
+	/*
+	 * change to the directory for a moment,
+	 * and then do the getwd() (and get back to where we were).
+	 * This will get the correct path name with "../" things.
+	 */
+	p = strrchr(fname, '/');
+	q = strrchr(fname, '\\');
+	if (q != NULL && (p == NULL || q > p))
+	    p = q;
+	q = strrchr(fname, ':');
+	if (q != NULL && (p == NULL || q > p))
+	    p = q;
+	if (p != NULL)
+	{
+	    if (getcwd(olddir, BUFSIZE) == NULL)
+	    {
+		p = NULL;		/* can't get current dir: don't chdir */
+		retval = NULL;
+	    }
+	    else
+	    {
+		if (p == fname)		/* /fname		*/
+		    q = p + 1;		/* -> /			*/
+		else if (q + 1 == p)	/* ... c:\foo		*/
+		    q = p + 1;		/* -> c:\		*/
+		else			/* but c:\foo\bar	*/
+		    q = p;		/* -> c:\foo		*/
+
+		c = *q;			/* truncate at start of fname */
+		*q = NUL;
+		if (mch_chdir(fname))	/* change to the directory */
+		    retval = NULL;
+		else
+		{
+		    fname = q;
+		    if (c == '\\')	/* if we cut the name at a */
+			fname++;	/* '\', don't add it again */
+		}
+		*q = c;
+	    }
+	}
+	if (getcwd(buf, len) == NULL)
+	{
+	    retval = NULL;
+	    *buf = NUL;
+	}
+	/*
+	 * Concatenate the file name to the path.
+	 */
+	if (strlen(buf) + strlen(fname) >= len - 1)
+	{
+	    printf("ERROR: File name too long!\n");
+	    myexit(1);
+	}
+	add_pathsep(buf);
+	strcat(buf, fname);
+	if (p)
+	    mch_chdir(olddir);
+    }
+
+    /* Replace forward slashes with backslashes, required for the path to a
+     * command. */
+    while ((p = strchr(buf, '/')) != NULL)
+	*p = '\\';
+
+    return retval;
+# endif
+}
+#endif
+
+/*
+ * Remove the tail from a file or directory name.
+ * Puts a NUL on the last '/' or '\'.
+ */
+    static void
+remove_tail(char *path)
+{
+    int		i;
+
+    for (i = strlen(path) - 1; i > 0; --i)
+	if (path[i] == '/' || path[i] == '\\')
+	{
+	    path[i] = NUL;
+	    break;
+	}
+}
+
+
+char	installdir[BUFSIZE];	/* top of the installation dir, where the
+				   install.exe is located, E.g.:
+				   "c:\vim\vim60" */
+int	runtimeidx;		/* index in installdir[] where "vim60" starts */
+char	*sysdrive;		/* system drive or "c:\" */
+
+/*
+ * Setup for using this program.
+ * Sets "installdir[]".
+ */
+    static void
+do_inits(char **argv)
+{
+#ifdef DJGPP
+    /*
+     * Use Long File Names by default, if $LFN not set.
+     */
+    if (getenv("LFN") == NULL)
+	putenv("LFN=y");
+#endif
+
+    /* Find out the full path of our executable. */
+    if (my_fullpath(installdir, argv[0], BUFSIZE) == NULL)
+    {
+	printf("ERROR: Cannot get name of executable\n");
+	myexit(1);
+    }
+    /* remove the tail, the executable name "install.exe" */
+    remove_tail(installdir);
+
+    /* change to the installdir */
+    mch_chdir(installdir);
+
+    /* Find the system drive.  Only used for searching the Vim executable, not
+     * very important. */
+    sysdrive = getenv("SYSTEMDRIVE");
+    if (sysdrive == NULL || *sysdrive == NUL)
+	sysdrive = "C:\\";
+}