This computer is not running genuine Windows.

[Sysman]

And you still get windows updates? I tried the uninstall, rebooted, now windows update tells me the service isn't running.

To be fair, I switched off and went to bed at that point so maybe it's okay.

Not sure about Win7 but when this happened to me with Win8, the updates kept coming and it got me through a Patch Tuesday OK.

I had to look carefully but somewhere on the warning screen was a button to press for re-activation.

Needless to say, reactivation wasn't the simple process they claimed it to be. The twunts really want you to buy another licence.

I've seen claims that reactivation can be done via the internets, and maybe that's the case for US customers, but I had to do it by phone.

Activation tips:

First of all, gird your loins for an unpleasant experience.

• if you operate a swearbox, buy a bulk contribution; you might need it
• bear in mind that it is not in Microsoft's interest to make this easy - their unstated aim is to make you buckle and cough for a new licence

1. take a screenshot and print it out; the default font is too small to read when your eyes are filled with tears of rage, so enlarge the image it before you print
2. you will want to write the results down, not enter them directly into the computer; arm yourself with a reliable writing implement, plus backup just in case
3. if they offer an international toll-free number ignore it, 'cos it didn't work for me
4. don't hangup when it sounds as though you have a bad connection, this happens every time you call and is part of the Windows Activation Experience
5. once you have battled your way through the voice menu, you are ready to start bashing in the numbers on your printout
6. the numbers are in groups of 7 digits; times 9; there must be a check digit involved because if you get a group wrong the system tells you so straight away and asks you to input it again
7. Oh, did I mention that the above step doesn't work on the kind of smartphone that dims the screen when you hold it to your head? Hang up and dig out your hands free kit.
8. repeat step 7 using the hands free kit, only to discover that after typing a group of numbers the screen dims anyway and you lose your place
9. have a moment's regret that you gave up your landline
10. remember how much that landline cost and what a hassle it was to get fixed when it went down, and decide you made the right decision
11. dig out that ancient but trusty Nokia from your cupboard and start again
12. Finally you get to hear the activation code which is also done in groups of digits; you get the chance to go back for a repeat or go forward after each group, and there's an option to have the lot repeated at the end; for the sake of your sanity, do go for the repeat

At this point a good cup of tea is probably your best option.

Next, enter the codes into the Activation screen, wait for a bit and savour how you have beaten a system which really wanted you to cough up again for a fresh licence.