Guys I need help. When I try preload phase 3 of HL2, when i click 'continue', a 'validating cache' thing window appears, then disappears shortly after, but doesnt download.
The only known solution is to start again from scratch. There's plenty of time, so don't worry.
You could also try moving one or more HL2 files to the desktop, starting the pre-load, exiting Steam and moving them back again then continuing further.