Howdy. The SiS 900 Fast Ethernet controller is an integrated ethernet card.
You mentioned that there were 'two internet connections' - and I bet one almost always said "Network cable unplugged"?
You friend didn't delete your internet connection, he disabled the ethernet card.
If you want to re-enable it, go to the Device Manager (I find it easiest to right click on My Computer -> Properties -> Hardware tab -> Device Manager), click the plus next to Network Adapters, then look for any red Xs or yellow question marks. If you see a red X, then that device is disabled. You can right click -> enable.
Now, your printer shouldn't be related in any way to the ethernet card, but if your printer isn't a thousand years old, then your printer might be hooked up to your PC via USB cable.
Find the cable that goes from your printer to your PC. How does it hook up to your PC? Does it look like this?http://www.xkeys.com...eys/usb-432.jpg
If it does, go back to the device manager, and go all the way to the bottom to Universal Serial Bus controllers. If any of them are disabled, enable them.
If this doesn't help, update your motherboard drivers. Just curious, what model motherboard do you own?