I have a large(45Mb) text file that I need to edit on a Vista x64 machine. Notepad won't open it, as it's too big. Wordpad can open it, and until recently, could edit it too. Now, although nothing has changed, the file opens and is displayed, I can't make changes. This is the same for several similar files. Small ones (~25Mb) work okay, and can be edited. The file is not read only, and I have write permissions on the file. One oddity - If I select "Insert->Time and Date" then the time and date is inserted, then I can delete that and edit the file as normal. I can't use any other software, as we can't install anything else here. Thoughts?