Unne: Uninstall windows.

Arche: Put a strong magnet next to your harddrive.

Now that's out of the way...

1. Nothing terrible should happen as a result of disabling System Restore - but in the event your computer gets totally screwed by a virus, you obviously can't restore it to a previous state. I'm not surprised Windows wouldn't let you access it, but I'm curious as to how it harbors viruses, as I've never had a problem with it. I've never had any problems with it, really, so I'm wondering what exactly went wrong with yours and whether I need to be aware of it. But anyways, nothing bad should happen. Just keep your OS cd around, and backup your special important files.

2. I'm assuming you mean restart your computer... I used to have a problem similar to this with my wireless card, and what I did was disallow Windows to automatically configure my wireless settings, and then it maintained my connection permanently. I don't know if there's an analogous or isomorphic operation of that to your situation here. I get the feeling it may be a hardware issue with your computer's modem - maybe it can't handle the quantity of data you're downloading and uploading and result in a buffer overflow. Usually when that happens, it shuts down and you have to restart the modem or your computer.

And you may want to try AdAware for more indepth scanning and stuff - I've found it to be more effective.