I'm no expert on the byzantine catacombs of Windows activation, but I suspect that you just need to have windows check its validity, as it sometimes wants to do. You said you rolled back some updates via Restore, and so Windows probably thinks it needs to check in with the mothership (and thinks it hasn't done so since before the restore point, which is probably "too long" ago). I'd suggest running Windows Update manually and see what it queues up in terms of things it wants to install. Likely one of those will be the "genuine" check that shows up with updates periodically, and running that will put you back in the good graces of Windows activation. You should probably think about installing some of the other updates as well, at least the ones that are security-related. (I know updates seem to have been the cause of your recent problems, but you don't want an unpatched machine).
In the worst case, you have an OEM laptop so it's not like the nice people at Microsoft India (or wherever they're doing phone activation these days) will think you're a pirate if it comes to that.
Aside: there are tools (such as SIW
and various others you can find if you google with the obvious keywords) that can extract and decrypt the activation code for your copy of Windows; it's always a good idea to make a copy of that somewhere in case a reinstall becomes necessary (perhaps you'll want to write it on a piece of tape and stick it on your laptop).