Disc Cleanup W7

[#1]

I began to run out of space on my 60GB SSD (down less than 1GB free) so set about manually deleting some files but only got it up to just over 3GB.
I then ran Disc Cleanup where over 5GB of Windows Update files were found. The box was ticked so I clicked OK to delete them but the free space remains at 3GB.
There's nothing in the Recycle Bin and running Disc Cleanup again shows just 2MB of Windows Update files left.
So, why isn't the deleted 5GB now showing as free space?
Any ideas?

[#2]

It's at the back of my mind that I've noticed something like that, and it doesn't show up until after a restart - not SSD though!

[#3]

Sheer coincidence but we had a power outage soon after posting.
On reboot it showed a message that Windows was updating and once to desktop there the files were ... gone 

[#4]

Do you keep the device on 24 / 7
If so
I always recommend, completing a reboot before applying any major changes

[#5]

Yes, it's on 24/7.
I don't remember there being any updates this week, though.

[#6]

Them sneaky little critters are everywhere
Don't tell me Window Definition was amongst then ?
Also use Ccleaner / if you haven't already

[#7]

It was the windows update cleanup that triggered the boot time messages about configuring updates.

[#8]

Not sure of what make of SSD's you have  but Samsung magician is a handy tool to have.

[#9]

I would suggest that you clear out all the old system restore points with the exception of the latest one (you should be able to do this from the disc cleanup when you are in the more advanced section) if you have it active as that will get you a few gigs of space back.