Windows 7 Pro suddenly de-activated

In that case, it's counterfeit
COA_SLP Keys are the ones that come on COA stickers, where the OS is pre-installed by major manufacturers.
There are a number of scams operating, where 'shops' are selling Branded OEM disks with 'COA stickers' which may or may not be either OEM or Retail/MSDN Keys.

Who was the supplier for the OS?

....also, disks accompanying a COA_SLP Key would not be hologrammed, normally, but branded by the manufacturer.
I suggest that you look closely at teh disk!

If it was AMazon, then complain to them - it's probably worth your while also to try telephone activation in case we're missing something....


telephone activation (operator calls)
Click on the Start button
in the Search box, type
SLUI 4
and hit the Enter key
follow the instructions, but when asked which service you require by the telephone ansafone, do NOT reply - this should force an operator to respond, who can deal with you


....ask them specifically for the reason for the block, if they can't clear it

Yes - a genuine Retail Key can simply be swapped in using the Change Product Key link, or the 'SLUI 3' command.

Pro Retail Win 7 in the UK -
Microsoft Windows 7 Professional English DVD (FQC-00133) - dabs.com (£166)
Windows 7 Professional Operating System, Retail - FQC-00133 - Scan.co.uk (£165 and change)

Have you changed the Key already?

Please post a new MGADiag report if so.