diff --git a/windows/winpgnt.c b/windows/winpgnt.c
index 49cd311f..0786f7a6 100644
--- a/windows/winpgnt.c
+++ b/windows/winpgnt.c
@@ -59,6 +59,9 @@ static int requested_help;
 char *help_path;
 static char *putty_path;
 
+/* CWD for "add key" file requester. */
+static filereq *keypath = NULL;
+
 #define IDM_PUTTY         0x0060
 #define IDM_SESSIONS_BASE 0x1000
 #define IDM_SESSIONS_MAX  0x2000
@@ -1410,30 +1413,21 @@ static int cmpkeys_ssh2_asymm(void *av, void *bv)
 static void prompt_add_keyfile(void)
 {
     OPENFILENAME of;
-    char filename[FILENAME_MAX];
     char *filelist = snewn(8192, char);
-    char *filewalker;
-    int n, dirlen;
 	
+    if (!keypath) keypath = filereq_new();
     memset(&of, 0, sizeof(of));
-#ifdef OPENFILENAME_SIZE_VERSION_400
-    of.lStructSize = OPENFILENAME_SIZE_VERSION_400;
-#else
-    of.lStructSize = sizeof(of);
-#endif
     of.hwndOwner = main_hwnd;
-    of.lpstrFilter = "PuTTY Private Key Files (*.ppk)\0*.ppk\0"
-	"All Files (*.*)\0*\0\0\0";
+    of.lpstrFilter = FILTER_KEY_FILES;
     of.lpstrCustomFilter = NULL;
     of.nFilterIndex = 1;
     of.lpstrFile = filelist;
     *filelist = '\0';
-    of.nMaxFile = FILENAME_MAX;
+    of.nMaxFile = 8192;
     of.lpstrFileTitle = NULL;
-    of.lpstrInitialDir = NULL;
     of.lpstrTitle = "Select Private Key File";
     of.Flags = OFN_ALLOWMULTISELECT | OFN_EXPLORER;
-    if (GetOpenFileName(&of)) {
+    if (request_file(keypath, &of, TRUE, FALSE)) {
 	if(strlen(filelist) > of.nFileOffset)
 	    /* Only one filename returned? */
 	    add_keyfile(filename_from_str(filelist));
@@ -1443,28 +1437,13 @@ static void prompt_add_keyfile(void)
 	     * rest the filenames. terminated with an
 	     * empty string.
 	     */
-	    filewalker = filelist;
-	    dirlen = strlen(filewalker);
-	    if(dirlen > FILENAME_MAX - 8) return;
-	    memcpy(filename, filewalker, dirlen);
-
-	    filewalker += dirlen + 1;
-	    filename[dirlen++] = '\\';
-
-	    /* then go over names one by one */
-	    for(;;) {
-		n = strlen(filewalker) + 1;
-		/* end of the list */
-		if(n == 1)
-		    break;
-		/* too big, shouldn't happen */
-		if(n + dirlen > FILENAME_MAX)
-		    break;
-
-		memcpy(filename + dirlen, filewalker, n);
-		filewalker += n;
-
+	    char *dir = filelist;
+	    char *filewalker = filelist + strlen(dir) + 1;
+	    while (*filewalker != '\0') {
+		char *filename = dupcat(dir, "\\", filewalker, NULL);
 		add_keyfile(filename_from_str(filename));
+		sfree(filename);
+		filewalker += strlen(filewalker) + 1;
 	    }
 	}
 
@@ -2223,6 +2202,8 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 	DestroyMenu(systray_menu);
     }
 
+    if (keypath) filereq_free(keypath);
+
     if (advapi)
 	FreeLibrary(advapi);
     return msg.wParam;
diff --git a/windows/winstuff.h b/windows/winstuff.h
index a6b22a8d..f6fae661 100644
--- a/windows/winstuff.h
+++ b/windows/winstuff.h
@@ -173,6 +173,10 @@ struct ctlpos {
 /*
  * Exports from winutils.c.
  */
+typedef struct filereq_tag filereq; /* cwd for file requester */
+BOOL request_file(filereq *state, OPENFILENAME *of, int preserve, int save);
+filereq *filereq_new(void);
+void filereq_free(filereq *state);
 void split_into_argv(char *, int *, char ***, char ***);
 
 /*
diff --git a/windows/winutils.c b/windows/winutils.c
index b2921245..2e91d8bb 100644
--- a/windows/winutils.c
+++ b/windows/winutils.c
@@ -5,16 +5,89 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
+#include <limits.h>
 
+#include "winstuff.h"
 #include "misc.h"
 
 #ifdef TESTMODE
-/* Definitions to allow this module to be compiled standalone for testing. */
+/* Definitions to allow this module to be compiled standalone for testing
+ * split_into_argv(). */
 #define smalloc malloc
 #define srealloc realloc
 #define sfree free
 #endif
 
+/*
+ * GetOpenFileName/GetSaveFileName tend to muck around with the process'
+ * working directory on at least some versions of Windows.
+ * Here's a wrapper that gives more control over this, and hides a little
+ * bit of other grottiness.
+ */
+
+struct filereq_tag {
+    TCHAR cwd[PATH_MAX];
+};
+
+/*
+ * `of' is expected to be initialised with most interesting fields, but
+ * this function does some administrivia. (assume `of' was memset to 0)
+ * save==1 -> GetSaveFileName; save==0 -> GetOpenFileName
+ * `state' is optional.
+ */
+BOOL request_file(filereq *state, OPENFILENAME *of, int preserve, int save)
+{
+    TCHAR cwd[PATH_MAX]; /* process CWD */
+    BOOL ret;
+
+    /* Get process CWD */
+    if (preserve) {
+	DWORD r = GetCurrentDirectory(lenof(cwd), cwd);
+	if (r == 0 || r >= lenof(cwd))
+	    /* Didn't work, oh well. Stop trying to be clever. */
+	    preserve = 0;
+    }
+
+    /* Open the file requester, maybe setting lpstrInitialDir */
+    {
+#ifdef OPENFILENAME_SIZE_VERSION_400
+	of->lStructSize = OPENFILENAME_SIZE_VERSION_400;
+#else
+	of->lStructSize = sizeof(*of);
+#endif
+	of->lpstrInitialDir = (state && state->cwd[0]) ? state->cwd : NULL;
+	/* Actually put up the requester. */
+	ret = save ? GetSaveFileName(of) : GetOpenFileName(of);
+    }
+
+    /* Get CWD left by requester */
+    if (state) {
+	DWORD r = GetCurrentDirectory(lenof(state->cwd), state->cwd);
+	if (r == 0 || r >= lenof(state->cwd))
+	    /* Didn't work, oh well. */
+	    state->cwd[0] = '\0';
+    }
+    
+    /* Restore process CWD */
+    if (preserve)
+	/* If it fails, there's not much we can do. */
+	(void) SetCurrentDirectory(cwd);
+
+    return ret;
+}
+
+filereq *filereq_new(void)
+{
+    filereq *ret = snew(filereq);
+    ret->cwd[0] = '\0';
+    return ret;
+}
+
+void filereq_free(filereq *state)
+{
+    sfree(state);
+}
+
 /*
  * Split a complete command line into argc/argv, attempting to do
  * it exactly the same way Windows itself would do it (so that