Solution for: "Unable to validate that the file <name> matches the URL <url>"

[Doug]

I got this as soon as I installed Vis Studio 2003, which either
requires different permissions to inetpub\wwwroot or changed them
during installation.

I couldn't open an existing solution or create a new one. Very
frustrating.

The solution (for me, anyway) was to change the permissions to the
inetpub\wwwroot folder. I needed these permissions:

Administrators - all permissions
Everyone - Read & Execute, List, Read
VS Developers - all except "Full Control"

HTH someone.