For anyone still stuck:
I noticed that after I installed Half-Life 2(for the second time ..properly without errors), (In Steam) the "Updating starting.." next to it didn't move, after many PC and Steam restarts.
I tried everything everyone else suggested, and here's what worked for me:
Right-click Half-Life 2, go to Properties, Local files:
(1) Verify integrity of game cache
(2)[most importantly] Defragment cache files
Defragment, lastly as I did, worked for me. Though I don't know if this will work for everyone.
Bookmarks