Its possible that your host server permissions are set such that you cannot
overwrite the original index.htm file and index_files folder. You might need
to log on to your host and try to change the permissions, or perhaps rename
the files and the folder on your site by adding "old" to the file and folder
names, and then try uploading. If that works, then you can go back and
delete the old files and folder. If not, you can change the names back to
the original, and your site will work from those files.

You did not specify how you uploaded. If you are using FTP then I would
certainly try the above advice. If you switched from XP on your old computer
to Vista on your new one and are using HTTP uploading, then the problem is
probably associated with Vista. In that case I don't have a good answer if
you are using a form on your site, because you have to use HTTP uploading
protocol and FPSE on the host in order for the forms to work. And at this
point there are no great instructions on how to use HTTP uploading with
Vista. Read the thread by rjreily about http publisher problem on the 15th.
If you are using FTP, then I would suggest that you download and use the
freebie FileZilla FTP client. It is easier than trying to do it through
Vista.

DavidF