Many times the meter shows zero while it is still busy in the background and can take HOURS to download (slow connections cause this) or install (low performance / cheapo computers cause this) to install. Many times it may just be patience, and depends on alot of factors.
Normally go ahead before bed and click on up date. If it isn't done by the morning, then may need to reset the Update to clear out where it 'thinks' it should be to where it 'starts from scratch'.
I am assuming this copy of Windows not 'shared' or 'downloaded' correct?