When you attempt to connect to your ISP, or to sign up for something on the Internet, the process may try to download an .INS (Internet Naming Service) file. The download opens the File Download – Security Warning dialog, with a message similar to:
Do you want to open or save this file? Name: SomeFileName.ins Type: Internet Communications Settings From: Your_Network_Internet_Protocol_AddressIf you press Open, Internet Explorer prompts you to save the file, or cancel the .INS file download.
NOTE: Any response results in a failure to connect.
NOTE: This behavior can occur on any computer, but it is more likely with Windows XP SP2.
The behavior occurs because Internet Explorer considers INS files to be unsafe, and does NOT allow you to open them.
The only workaround is to contact your ISP for information on how to sign up.