Maybe these sound like skills that should be just as common as operating a telephone, but it's easy for nerds like us (before you contest it: you follow the exploits of a mentally-damaged 31-year-old video logger and unpublished comic artist) to forget that most people young and old can (and do) get what they need out of their computers without ever opening the control panel. You don't think Geek Squad's fucking ridiculous prices could persist if everybody's kid could swap out faulty hard drives, do you?
It's not like any of that is difficult or couldn't be performed by a 9-year-old with sufficient instruction. If you can work legos you can install computer hardware. Yeah most people don't trust themselves to swap out a hard drive but that's because they assume it's more complex than it is. Granted Chris can do some things that a lot of people won't try (rather than being unable to do) but it's just not indicative of any kind of talent or skill or ability. He's just capable of moving his MANOS and he took some rudimentary computer classes.
Also the stuff he can do is the most rudimentary of rudimentary computer stuff. Installing software? My grandmother can do that and she doesn't know what the internet is. Making an ugly webpage on Tripod can and has been done by children barely old enough to read. Many dogs have multiple facebook accounts. Nothing on your list besides installing an operating system is even sort of difficult, and that's really more of a matter of following directions and having patience (I doubt if a serious problem arose Chris would have successfully installed anything).
People give Chris a lot of credit for being able to stand up and form complete sentences, but really guys he's not the computer genius (or even computer adequate) that he's oft made out to be.