Joe -

I've encountered an assertion by Microsoft that there is a difference. Vista adds support for "more than three letters" in file extensions, and quite probably your save from notepad (in Vista) could have been done as .html. Microsoft states specifically that .htm and .html file endings "work differently" (in Vista) but don't describe any differences.

I've done a brief search at Microsoft to see if they'll tell me what the difference is (for Vista) but as is common for "anything Vista" all I get for search results is advertisments for Vista.

I'll try to watch this thread to see if anyone explains it to us.

John