Missing GCF's

Missing “c:\program files (x86)\steam\steamapps\half-life source.gcf” [-1]
Missing “c:\program files (x86)\steam\steamapps\base source engine 2.gcf” [-1]

I seem to be missing these 2 files ever since i updated to windows 8 pro, ive redownloaded all my games, i got all half-life2’s any ideas on a fix ?
I know ive done it before, like 2 years ago when people told me how to but i completely forgot …
So Any Help would be appreciated