Lenovo 1802 error

[Phil]

Thank you for reading this continuing saga.

Just to recap, I bought a refurbished Lenovo T420 laptop. All went well at until the 1802 (unauthorised network card) error occurred and now I cannot boot the computer. Occasionally I can but not very often.

An Internet search shows that this is a common problem. I have built a no-1802 boot CD but on the rare occasion that I can escape the 1802 error and can actually boot from the CD I'm informed that the CD is not a FAT format although I get a Windows prompt that allows me to continue but nothing seems to happen. The network card is still turned off.

I've attempted to disable the card in the BIOS and to open the case to remove the card, but no joy and the Ebay seller is not responding. F1 used to bring up the BIOS menu but that's not happening now. I really had reservations about buying a used laptop and it appears that those doubts have been vindicated.

Can anyone offer any suggestions?

-- 
Regards,
Phil