I have a three-year warranty for my laptop computer with Hewlett-Packard.
The start date of the warranty is wrong. When I emailed HP customer care to correct it, forwarding the original email response confirming my purchase, they wanted ‘a scan of the hardware invoice’, which I sent.
This begs two questions:
1. what use is the ‘confirmation’ email about a purchase? Surely HP have the same email, which is all they need to confirm the purchase.
2. what if I did not take a copy of the hardware invoice, what then?
As usual, the customer has to do all the running with each vendor, whose job it is to keep records of their sales.
Update:
2 Aug 2018: I came across Are invoices necessary to claim warranty for HP laptops?
Donald's Thoughts 
On a nigh-daily basis, I get phone calls wanting me to allow supposedly computer technicians to check that my computer is working properly. 99.9/100 times when I attempt to check its a genuine call or not, I discover the number called is “NOT VALID”
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Yes, David,
Many of these cold calls are scams. On no account should you allow a cold caller to have access to your computer, nor should you accept any of their ‘free’ software.
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