Ok:So did you follow the above checklist and everything is as it should be and the necessary services are active ?
Is this a home built pc or ??
Generally,when you have device issues after a reformat/re-install,it turns out to be a device driver or chipset driver issue.
If store bought,the best place to check is on the makers web site.
Have you tried this hardwaired into the router and modem?
Let's take a look at device manager.like so
Let’s take a look at the status of the network adapters
Device manager:
Hold the Windows key and press R, then type devmgmt.msc
Please respond to all the following steps.
1. Under Network adapters, please tell me all the devices listed.
2. Are there any devices under Network adapters that have a red x displayed?
3. Also, are there any devices anywhere in the Device Manager display with yellow ? or ! displayed?
4. Adapter status should be “working properly and enabled”
Also,report any other devices(usb,etc) that appear in error status.
Then,let's check the network view of the pc that cannot access the net.Like so.
From a Johnwill post on the Networking Forum
Try these simple tests.
Hold the Windows key and press R, then type CMD (COMMAND for W98/WME) to open a command prompt:
In the command prompt window that opens, type type the following commands one at a time, followed by the Enter key:
IPCONFIG /ALL
PING <computer_IP_address> For addresses,follow instructions below….
PING <default_gateway_address>
PING <dns_servers>
PING 206.190.60.37
PING
www.yahoo.com
Right click in the command window and choose Select All, then hit Enter to copy the contents to the clipboard.
Paste the results in a message here.
<computer_IP_address> - The IP Address of your computer, obtained from the IPCONFIG command above. IPV4 for Vista
<default_gateway_address> - The IP address of the Default Gateway, obtained from the IPCONFIG command above.
<dns_servers> - The IP address of the first (or only) address for DNS Servers, obtained from the IPCONFIG command above.
If you are on a machine with no network connection, use a floppy, USB disk, or a CD-RW disk to transfer a text file with the information to allow pasting it here.
______