Urgent help needed

I'm having problems connecting to sites including symantec.com

 

Also have errors in event viewer as follows:

 

A compatable trusted platform module (TPM) Security device cannot be found on this computer.

 

Code integretity determined that the image hash of a file is not valid. The file could be corrupt due to unauthorized modification or the invalid hash could indicate a potential disk device error.

 

A logon was attempted using explicit credentials.

 

The browser has forced an election on Network\Device\NetBT_Tcpip_ {*********************************} because a master browser was stopped .

 

The IP address lease 1**.1**1.2 For network card with network address ********* has been denied by DHCP server 1**.1**.1.1 (The DHCP Server sent a DHCPNACK message)

 

The description for event id 1003 from source Microsoft=?Windows-DHCP client cannot be found. Either the component that raises this event is not installed on your computer or the installation is corrupted.  

 

These are just a few of the error messages I have found, I should just state that I only started having problems a few days ago when Norton 360 blocked an intrusion attempt  by 38.114.196.10  Risk name: HTTP Malicious Toolkit Variant Activity 2

This was a file on mediafire server from a trusted source, and it only happened as I entered password for the file. I know Norton said it blocked the attack, but I can't help thinking this is what has caused me these problems. Is it possible that it actually managed to damage my computer before Norton stopped it??? I don't know what to do now, I'm thinking it looks so bad that I'm probably going to have to re-format my harddrive, any advise would be welcomed before I take that measure.