Go to windows update and make sure you OS is up to date. If that doesn't work try reinstalling steam, and downloading HL2 again.
Are you using a non NTFS partition, or any other non standard disks (sofware raid etc)?
Good points, however if I wanted to kill things easily in new fun ways... I would set the difficulty to easy. A difficulty setting of hard, should be just that, hard!
I have not completed HL2 yet. I believe I am about two thirds through now, having formed up with my first squad about 20 mins ago. So far I haven't come up against anything that has been too hard. The only spot I have found remotely difficult was setting up the first set of turrets.
Has...
If you buy it on Steam now you can play it as soon as you have downloaded it. It might take you a while, and shouldn't be attempted on 56K uless you have a lot of time on your hands.
Oh... anf overclock you graphics card. I have mine running at 410MHz. Take a look at http://www.guru3d.com/ (and other similar sites) to make sure you have everything running as well as possible.
You should be able to... make sure you have the most up to date BIOS and graphics card drivers. Update windows, make sure you have no IRQ conflicts etc etc etc... and you will be fine.
The 'in' value, as you rightly say, is the rate your computer is receiving data form the server, in kb/s. If this rate gets close to the maximum rate your Internet connection can support, it shows your cl_updaterate setting might be too high, as could your cl_rate setting.
I have played...
For the record here's my theory.
I think the cannon mixes up, very quickly, a load of clear, unflavored, jelly mix. Once the jelly is set (presumably they use an alcohol or similar to mix it so it sets quickly) it is fired from the cannon using... air pressure. Once hit by the flying jelly...
I have never said it must be anything. In fact, I have not said what I think it is at all.
A number of people have posted commenting on your theories. And I believe there are two reasons why.
1) This is a conversation, and that's what happens in conversations.
2) You are saying what...
If you think that, you have misunderstood something.
You have made many statements which you give as fact rather than theory. One 'I think' in one post does not cover them all.
A cheap shot, I'd thought better of you. :P I have no desire to prove I know more than you. Just to show the...