The piece of sh!t VALVe designed. Steam started as a VERY buggy program. After Steam deleted all the HL files from your HL folder, people found that Steam is the worst piece of sh!t ever made, but they had to stick with Steam after they had no more HL files. Not only that, Steam downloads upgrades and other crap without notifying you about it at ALL. That means that if someone can hack into the download manager of steam, they can put viruses, spyware and all the other sh!t they want without you knowing it. MILLIONS of people support that and all the other facts why steam is crap.