Odd behaviour

[#1]

Do you have something like a TV tuner in the system?
These usually require firmware to be loaded on the fly, on every boot, and you can get some odd behaviour when unexpected firmware is already loaded (i.e. Windows driver expects firmware X but Linux has loaded firmware Y).

[#2]

No TV tuner, just the standard things such as printer, loud speakers etc.
If something is loaded on boot up I assume it would be when Linux is booted up but cannot understand why that information would be retained following for a short period after shutdown.
Seems a mystery until someone else comes across the same or similar problem.

[#3]

When you shutdown Linux, do you also switch off the computer at the mains, or turn off the switch on the back of the PSU? If not it might be worth doing that, and see if it changes anything.
The hardware of my laptop will be left in a slightly different state if I reboot from Linux into Windows - Linux intentionally makes part of the card reader disappear, which won't re-appear after rebooting, into either Linux again or Windows. But that's rebooting, not shutting down and powering off.

[#4]

I Will check that out.
Thanks.

[#5]

@ejs
Turned the computer off at the mains, booted into windows no problem, so your suggestion worked.
Thanks
So even if you close down the computer in the normal way some power must still be getting to the SSD for a short period of time providing the computer is still plugged into the mains, does this mean that as long as a computer is plugged in the transformer is getting some current ? If so is it safer to actually unplug the computer ?

[#6]

the whole time the wall is switched on the transformer is fully powered, that's why the second you push the button on the front the system starts up,

[#7]

OK, but is anything still powered beyond the transformer when the computer is off, excluding of course the rechargeable battery ?
I am still trying to figure out the logic of the SSD retaining some data for a short period which it loses the instant the computer is unplugged.

[#8]

the simple answer would be to say "its all still connected", until you pull the plug, the reason why all maint procedures start with unplugging the pc is to get rid of the power, and (if your system has one) the mobo power led will be lit 24/7 and you shouldn't start pulling stuff out of the system until that light has gone out after pulling the plug.
in practice things are a lot more complicated and the answer changes depending on the different parts you have in your case, and indeed what case you have.
my system for instance the power switch on the back of the psu does nothing (its currently in the off position and has been for weeks) everything is controlled by the motherboard  (I thought it meant my psu was faulty but I've been gened up on things by the manufacturer) yet the same psu used in a different system with a different mobo and the switch on the back works as expected ......