HTTP 404 - File not found ??!!

Hello,

I am getting the error message "HTTP 404 - File not found" for files
in one folder whereas no problem accessing the same files which have
been copied into a second folder?!

I can access other files in the first folder which were created before
I reinstalled XP Pro and iis (v5.1).

Also, I used to be able to use Windows Explorer to change file
folder/file permissions but that no there now!>

Odd? Ideas please?

Cheers

Geoff