TalkTalk Mail Address Book contacts can be exported as a CSV file or vCard.
Repeat for other address books including Collected addresses which is the list of contacts you've sent to.
The above assumes you can import contacts in CSV format. If you wish to import to Windows Mail that doesn't directly support CSV file format then let me know as there's a workaround I can offer you.
You're very welcome.
TalkTalk is certainly going through a strange phase. I've experienced being treated unfairly so I appreciate exactly what you're saying.
But I'm still here soldiering on and helping other members as best as I'm able.
Enjoy your weekend.