...it sleeping or hibernating? Unfortunately, you've not told us which operating system you're using, or anything else about your computer but some of the Windows 7 and 10 updates are extremely large now and if your computer went to sleep while downloading or attempting to update, then you'll want to wait longer.. If it was actually running for the entire time, I'd restart the computer (it shouldn't actually ruin anything, it just won't install the updates), and immediately run Windows Updates manually after the restart.

Hope this helps.

Grif