Unable to open Outlook Archive File

I realise I have probably been stupid but I have an Outlook (2000) archive file of 2076320kb and when I try to open it, I get the message “Properties for this service must be defined prior to use.” On clicking OK, a dialog opens saying “Errors have been detected in the file C:\My Documents\Outlook Files\archive.pst. Quit all mail enabled applications, and then use the Inbox repair Tool.” When I use Scanpst it runs OK to stage 4 of 8 (which it completes) and then a dialog opens: “Scanpst: This program has perfromed an illegal operation and will be shut down. If the problem persists contact ….. etc.”
I am now stuck and don’t know how to get the archived emails, notes etc back. Can anyone help me to recover the file or parts of it please?
Thanks,
John