vbsp.exe is corrupted.

[Tex20]

I just verified my game cache, and 7 files were missing, when it finished downloading the files, it says it failed, because vbsp.exe (located in the bin folder in Portal 2 directory), was corrupt. I've tried everything. I even tried reinstalling Steam! Nothing seems to help.

[cheshirm]

rename it like vbsp.junk so that it occupies the same area on the disk. then do verify game cache again. steam "should" download a working vbsp.exe. it that works, delete vbsp.junk.
might check the hard drive/file system for errors. might be permission problem - run as admin.