Persistant undo, my saviour

vimrc

@@ -199,6 +199,20 @@ filetype on
 filetype plugin on
 filetype indent on
 
+" Put plugins and dictionaries in this dir (also on Windows)
+let vimDir = '$HOME/.vim'
+let &runtimepath.=','.vimDir
+
+" Keep undo history across sessions by storing it in a file
+if has('persistent_undo')
+    let myUndoDir = expand(vimDir . '/undodir')
+    " Create dirs
+    call system('mkdir ' . vimDir)
+    call system('mkdir ' . myUndoDir)
+    let &undodir = myUndoDir
+    set undofile
+endif
+
 map <up> <nop>
 map <down> <nop>
 map <left> <nop>