Can't download any updates or anything else really

I have just formatted for the first time a brand new 500GB WD harddrive with Asus motherboard, AMD Athalon 64 processor, 4GB RAM, etc... and cannot download any service pack updates, internet explorer 7 (or 8), google chrome, itunes, norton antivirus or anything else it seems. As for anything Microsoft related I keep getting the message that the Publisher is Unknown and then EXTRACTION FAILED: FILE IS CORRUPT.

Everyting that isn't Microsoft simply goes to EXTRACTION FAILED: FILE IS CORRUPT without giving any other reason.

Please give me some idea what's going on! I'm exhausted with this thing.

 

Oh yeah. I forgot to mention that I am using XP Home and it's the original. Don't know if that makes a difference.

HELLLLLP!!!!!