A suggestion that I have found vastly increases the chance of a successful export from Windows XP.
Make a separate folder in a disk with lots of free space and put
only the world you want to export in that folder. Then edit the world as desired. Before you try to export, check that folder and delete anything that may be there other than the world. Now reboot your computer to clear any "memory leak" problems and try the export. Hopefully it will work - if not you may be able to get a clue from the content of the frames folder that was created or the error messages. If it fails, Alice will also now run quite slowly, so I again suggest rebooting your system before going further.
The good news

is that the .mov file that is generated by Alice seems to be a fairly standard file. I had no trouble converting the file that was generated to other formats using AVS Video Convertor ( from
http://avs4you.com/ ) - something that is
not always the case.
For Windows users, getting to .wmv format is quite useful since it lets you use Movie Maker and other Windows specific tools. In particular, Movie Maker will let you add or fix any sound track problems that you may have. Also, .swf is a fairly standard Flash format for Web postings, etc. Both conversions, as well as one to the DviX version of AVI (good for You Tube, though probably not necessary) worked fine, at least for the simple example I was working with.