CPU disconnects from the Internet but is still connected to the modem

CPU disconnects from the Internet but is still connected to the switch / modem.

After being hit with 3 viruses (all cleared) my Internet drops after a unspecific amount of time.

Symptoms:

Pinging the Gateway shows no connection despite the actual connection to the Linksys wireless router being in tact.

The repair function states that it can not renew the IP address

Safe mode in Networking does not show the network card or allow connections (page not found)

Other computers in the workgroup can not connect


Steps taken to fix:

Restoring to an earlier date

lspfix

combo fix

winsockfix


Motherboard: ASUS K8N with built-in Nic card (tried to reinstall the drivers
and the NIC disappeared and I had to restore to get the NIC card back-Device Mgr.)

How are you set up? router, wireless, modem, usb etc? Wireless router via Comcast LAN Cable

Do you run a network with more than 1 PC? 3 PCs and 1 Laptop (All others stay connected or if there is a hiccup the others go back online)

What is your provider? Comcast

Have you checked to see if they have some problem in their network? No unusual issues

Do you have Norton I.Sec or any firewall installed? Mcafee

No issues via Device Manager

No forced hardware

Ipconfig - release and renew has no effect- can not renew the IP address

Repair - Can not renew the IP address

Ping -t gateway- Can not reach gateway

Checks of the application logs do not reveal anything specific or repeated.

MBAM, Ad-Aware and Mcafee (reinstalled to no avail)

It does not allow removal, stating that it may be needed for booting. This happens in normal as well as Safe mode (Networking).